BHO Extraction

Butane Honey Oil, or BHO, is the essential oil from the cannabis plant, extracted using n-Butane as a solvent.  If it is extracted from fresh material, it is a Concrete, and if from cured material, it is an Oleoresin.  A concrete or an oleoresin that has been winterized to remove the waxes, lipids, and fats, is known as an Absolute.

Butane Honey Oil extraction refers to the method used to extract the essential oils from cannabis, and there are multiple theories on the best way to accomplish this, as well as what material is best to use.

Perhaps the first question is why use a BHO technique to extract the resins, instead of just boiling the material in alcohol to get the greatest amount of extracted material?

The answer to that is that because butane is relatively non polar, it doesn’t extract the water solubles like chlorophyll and plant alkaloids. Butane produces one of the cleanest extractions, albeit typically at a lower yield than polar alcohol.

On average we have extracted about 18% oil by weight from bud, but as low as 5.7% absolute and as high as 25 absolute%.

The first wash will usually extract 75 to 80%, leaving the balance for the second after repacking the column. The second extraction will be more sedative and less heady. If you use a hand microscope, you can easily see when the trichome heads are gone and the stalks look like wet fur.

We’ve only tried a few processes here at the pharm, so I will cover only simple flow through columns, a thermos bottle, a pressurized system, and a closed loop one.

We currently use a closed loop system for BHO, and as I am covering that process on a separate thread named The Terpenator, where I will detail building our second generation automated system.

Prior to using our DIY closed loop system, we did our BHO extractions using single pass flow through packed columns, and experimented with a thermos and a simple pressurized system to soak at ambient temperature.  I will cover simple columns and thermos bottles separately, as the techniques are different and I need to make some more pictures for the latter.

Before we discuss how to extract the essential oils from cannabis, let us talk about the plant material to be used.  That immediately brings to mind the qualifying question, “What do you want to use it for?”

Oil that is to be vaporized, is normally treated differently than oil that is used orally or topically, because it doesn’t need to be decarboxylated.  For cannabis concentrates to be orally and topically active, it does require that the THCA and CBDA be converted to THC and CBD, by a heating or drying process.  I will cover that issue under a separate thread on Decarboxylation, so as to not clutter this post.


Besides the cannabinoids, which are Di-Terpene alcohols and di-alcohols (diol), there are also other terpenes in cannabis essential oils, which add to its smell, flavor, and medicinal entourage effect.  Some of these terpenes are highly aromatic alcohols, phenols, ketones, aldehydes, ethers, and esters, which are aromatic because they freely give off molecules at even ambient temperatures.

Heating the plant material or the oil to decarboxylation temperatures will evaporate off most of these smaller aromatic Mono-Terpene and Sesqui-Terpene molecules, before the larger and heavier cannabis Di-Terpenes are affected.  Decarboxylated oil is smoother to the taste, but basically tastes like hash, with the floral undertones gone.

Gone also are the medicinal and entourage effects from those terpenes.  The price we pay for decarboxylation, so we shouldn’t decarboxylate casually, and should first consider the end use before picking the process.

One of our process  limitations, is that though non polar, n-butane has slight water solubility.  At 20C/68F, it is only 0.0325 percent by vol/vol, but not zero and is still  enough to pickup undesirable water solubles.  1 liter, or 1000 ml X 0.0325 = 32.5 ml of  water.

With water, comes water solubles, which includes chlorophyll and plant alkaloids, that detract from the taste, so the dance is to maintain the volatile terpenes, while studiously avoiding the water solubles.

Freezing the water is one method that works well, but it is important that the material be dry when it was frozen and that it is not exposed to high humidity while frozen, or ice will form over the trichomes, preventing their extraction.

Another method is to simply remove most of the water.  This will produce pristine extractions, but doesn’t preserve the terpenes.  If the material is to be decarboxylated anyway, that is of little concern, because we will lose them anyway.

We also have the issue of purging out the remaining butane, while preserving the terpenes.  Again, there are a number of ways to do that, but I will address only a few of the ways that have worked for us here.  Those are light heat, high heat, and thin film vacuum.

So, besides decarboxylation, what are some of the things to consider selecting a process and how should the plant material be prepared?

In our experience, for best flavor and taste, freshest material works best, whether it is fresh frozen material or dried.  Older cured material loses the nuances of the floral undertones and just tastes like hash.  That means that the degree of drying and curing is also critical, if your goal is to maintain maximum terpene content.

Oil from buds is tastier than oil from even sugar trim, because most of the terpenes are produced by the buds, and that is where they are the most plentiful.  Tasty is usually not a word used to describe oil from fan leaves or stems, though effective may be.

The absolutely most flavorful BHO extract to me personally and to the test panels thus far, is fresh picked buds, that are immediately frozen to tie up the water, and extracted while still frozen.  It produces an oil that abounds in whimsical flavors darting about and the word most often used to describe it by panel members, was the word “fresh.”

Next most flavorful, from a BHO standpoint, is material that has only been cured 5 to 7 days, and is at the small stem snap stage, where you might jar it if you were curing it to smoke.

Part of the formula is of course the degree and methods used to purge out the remaining butane.  While there are a number of ways to do that as well, I will address only a few of the ways that have worked for us here.  Those methods are low heat, high heat, and thin film vacuum.

Butane supply:

Lastly, selecting a suitable butane source is a key  step, in that all butane sources aren’t created equal.  n-Butane (normal butane) is a simple alkane, with four carbon atoms linked together in a row, with the remaining possible carbon bonding sites taken up by hydrogen atoms.

The simple alkanes all are gaseous at room temperature and atmospheric pressure.  They are removed from crude oil before it is further processed, by simple heating.  The simplest is Methane, which is only on carbon and four hydrogen atoms, followed by Ethane with two carbons, Propane with three, and Butane with the four.

Pentane is the next simple alkane, the first to be liquid at room temperature and the first to have zero water solubility.  From Pentane on, the simple alkanes are named from the Greek alphabet, and are Hexane, Heptane, Octane, etc, on through the light naphthas, oils, waxes, and asphalts.

The formula for all simple alkanes, is the number of carbon atoms times two, plus two, because each carbon atom has four possible bonding sites.  A mnemonic device for remembering the first four alkanes, which were named before the Greek system was applied, is Mary Eats Peanut Butter.

After removal from the crude oil, the gases are typically de-sulfurized using steam and a catalytic reactive bed, and fractionally distilled into the four basic gases.  As fractional distilling separates the gasses by specific gravity, the principal contaminants in n-Butane at that point, will be Iso-Butane, a branched molecule isomer of n-Butane, as well as n-Propane, and Cyclo-Propane, plus low levels of heavier, longer oleaginous alkane wax chains.

Neither of the butanes or propanes are particularly toxic at any sort of reasonable levels.  The following for instance is taken from a typical MSDS sheet for n-Butane.   The Rat LD-50 (50% dead) is 658000 mg/m3 4 hours.  That is breathing a 65.8% pure butane atmosphere and asphixiating.

MSDS info:

Section 11. Toxicological information for n-Butane; Diethyl; Freon 600; Liquefied petroleum gas; LPG; n-C4H10; Butanen; Butani; Methylethylmethane; UN 1011; UN 1075; A-17; Bu-Gas.

Specific effects

Carcinogenic effects No known significant effects or critical hazards.

Mutagenic effects No known significant effects or critical hazards.

Reproduction toxicity No known significant effects or critical hazards.

No specific information is available in our database regarding the other toxic effects of this material to humans.

Chronic effects on humans May cause damage to the following organs: central nervous system (CNS).

Other toxic effects onhumans

Toxicity data

Butane LC50 Inhalation Vapor

Rat 658000 mg/m3 4 hours

Product/ingredient name Result Species Dose Exposure

Products of degradation: carbon oxides (CO, CO2) and water.

Section 12. Ecological information

Products of degradation :

Environmental fate : Not available.

Environmental hazards : No known significant effects or critical hazards.

Toxicity to the environment : Not available.

Aquatic ecotoxicity

Not available.

The MSDS LD-50s on Iso-Butane, Propane, Cyclo-Propane, and oleaginous waxes are as follows:

n-Propane; Dimethylmethane; Freon 290; Liquefied petroleum gas; Lpg; Propylhydride; R 290; C3H8; UN 1075; UN 1978; A-108; Hydrocarbon propellant. LC50 Inhalation Gas:  Rat >800000 ppm 15 minutes

Cyclopropnane; Trimethylene; Trimethylene (cyclic); UN 1027;  No LD-50 established;

Iso-Butane; 2-methyl-; Trimethylmethane; 1,1-Dimethylethane; 2-Methylpropane; isoC4H10; i-Butane; Isobutane mixtures; UN 1075; UN 1969; R 600a; tert-Butane; A 31;Methylpropane; Propane, 2-methyl-isobutane LC50 Inhalation Vapor Rat 658000 mg/m3 4 hours

Oleaginous Waxes- Paraffin, no notable toxicity or LD-50 available

n-Butane is used for any number of things, so it is processing beyond this point, or sharing storage tanks with other contaminated sources that may create health concerns.  While n-Butane is non-toxic enough used as a food propellant, if it is to be used as a stove fuel, it will in most cases have an odorant added for leak detection, as n-Butane has only a very light sweet petroleum odor.

Ethyl Mercap is most often added for that purpose, and is the familiar rotten egg smell is detectable at the astonishing low concentration of under 3 parts per Billionth!   Hexane (Gasoline) by comparison, has an odor threshold of around 30 parts per millionth, or about 10,000 times more is required for us to smell mercaptoethanol.

The MSDS for Ethyl Mercaptan shows 4420 ppm/4 hour(s) inhalation-rat LC50; 682 mg/kg oral-rat LD50, with the target organs being the central nervous system.  Not super toxic, but tastes and smells of rotten eggs, so that point may be mute.

Butadiene may be added to stove fuel as well, and is of serious concern.  While the following typical MSDS example shows relative low toxicity, take a look at the carcinogenic effects.

LD50 Oral Rat 5480 mg/kg -LC50 Inhalation Vapor Rat 285 g/m3 4 hours

LC50 Inhalation Vapor Rat 285000 mg/m3 4 hours

LC50 Inhalation Gas. Rat 128000 ppm 4 hours

Mutagenic effects No known significant effects or critical hazards.

Reproduction toxicity No known significant effects or critical hazards.

No specific information is available in our database regarding the other toxic effects of

this material to humans.

CARCINOGENIC EFFECTS: Classified 1 (Proven for humans.) by IARC, 1 (Known to

be human carcinogens.) by NTP, + (Proven.) by NIOSH, 1 (Proven for humans.) by

European Union. Classified A2 (Suspected for humans.) by  ACGIH.

MUTAGENIC EFFECTS:  Classified 2 by European Union.

May cause damage to the following organs: the reproductive system, mucous membranes, upper respiratory tract, skin, eyes, central nervous system (CNS).

n-Butane may also be further refined to increase its purity, or to make it suitable for use in butane lighters.  R-600 Refrigerant and Instrument grade n-Butane are examples of higher purity n-Butane suitable for extractions, and are distributed by suppliers like Matheson and Airgas.

Lighter Butane:

As those sources are expensive and not usually available to non commercial customers, in support of federal guidelines listing it as a controlled substance used in the manufacture of illegal drugs, most folks use butane made for butane lighters.

Each manufacturers blend is slightly different, with n-Propane usually added as a propellant, because below the freezing temperature of water, butane is a liquid instead of a gas.

They also further refine the n-Butane to remove more of the low level oleaginous waxes, which clog  the small orifices in expensive butane lighters.  This is often shown on lighter butane cans as a number followed by an X.  IE:  5X.

The common name for Oleaginous Waxes from petroleum, is Paraffin, which is non-toxic enough to have no known LD-50 data and be used to seal jelly jars, so they are of low concern when extracting.

Here Madison Avenue has gotten a foot hold, and even 7X butane is available for even more money, though there is no advantage over a good 4X for the purpose of extraction.

One refiner has started labeling the brand names that they produce, Near Zero Impurities, guaranteeing under 50ppm impurities.  An independent test showed that they in fact are under 50 ppm, and even under the 15ppm testing cutoff, as were competitors brands not touting near zero impurities.

If using lighter butane, the safest course is to use tried and proven brands, but if forced to improvise, first obtain a MSDS sheet from that specific manufacturer, showing the contents.  Reject any containing mercaps or Butadiene.

Ingredients less than 1% need not be shown on the MSDS sheet, unless they present a health risk at the levels present, so they are not all inclusive, but a good place to start.

If the MSDS looks OK, spray a five second burst on a mirror or clean glass pane and let it completely evaporate.  Check for residue.  Smell it for mercaps; you can’t miss them.

Each brand extracts slightly differently, because the mixes are slightly different.  Adding propane for instance, increases water solubility and the propensity to pick up water solubles.

Here are some brands that we’ve tried and work well, as well as being tired and proven brands by others.  This list is by no means inclusive:







Butane is highly flammable, so let us next talk about safety. First and foremost, always perform the extraction outside in a well ventilated area.  Have a fire extinguisher handy, as well as a blanket to roll up in, should the unthinkable happen.

It goes without saying that smoking around a butane extraction is asking for a disaster, but I have literally grabbed the hand of folks starting to light up because they “forgot” where they were at and what they were doing. May I suggest that you leave your lighter and smokes somewhere else when you are doing extractions.

Same with your cell phone!

Wear no synthetic fabrics, including your socks, because static electricity sparks probably ignite more butane unintentionally than bone headed smokers.

We use a fan to disperse the butane rapidly so as to keep it from pooling. Butane is heavier than air and will collect in low spots given its own devices. We use a plastic fan so that no sparks are created by a piece of gravel or other hard material passing through the fan blades.

In dry cold conditions, we add a grounding strap to our cans, so as to not draw static electricity sparks between the can and the column.

Material Prep:

Material prep will of course depend on the application, so lets cover that subject generally.

Fresh buds should be dry of standing water and cut into small pieces, before being stuffed into a column or thermos and placed in a -32C/0F freezer for 48 hours to solidify.  Fresh frozen buds produce the most aromatic extraction.

Second best for for maximum terpene retention are buds ground up after 5 to 7 days hanging, or as soon as the small stems break freely.  They should be jarred immediately to retain freshness and run as soon as possible to prevent molding.

When extracting dried buds for vaporization, or bragging rights, the material is broken up just loosely enough to extract, but not enough to expose excessive broken cell boundaries.  That can be done by hand, or with a nugget buster.  Here is an example of a nug buster design that I scored off Roll It Up forum, but alas I can’t remember the author:  The wire cloth can be obtained from Howard Wire at

Nug buster-1-1

Nug buster base-1-1

Buds for decarboxylation and most pristine appearance, should be placed on a coffee sheet and baked in a 94C/200F oven until just frangible, when rolled between the finger and thumb.  They can then be ground or scrubbed through a pasta strainer to remove the sticks and stems.  They should be jarred after grinding, to keep moisture pickup low.

The material shouldn’t be bone dry as it will become too frangible, nor should a coffee grinder be used, because of the fines that it produces, that have to be subsequently removed.

We also dry our trim and leaves until frangible as above and scrub ti through a pasta strainer, using a leather gloved hand and firm pressure, so as to minimize the amount of fine particles generated.

So now that we have covered some of the basics, lets move on to the different processes:

Simple Flow Through Column:

One of the simplest methods of extracting using butane, is a packed column.  A column is a long narrow containment that allows a solvent to be passed though it using either gravity or pressure. The column is packed with plant material to be extracted and the essential oils are dissolved by the butane and carried out the filter in the bottom of the column, into a collection device.

Column materials:

Columns may be made from any number of different materials, but not all are suitable for butane service. is an excellent site to check material compatibility with the various solvents.  You do however have to read between the lines, and for medical use, stick with those materials listed as excellent.

Using those guidelines, a quick check reveals that Poly Vinyl Chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), Low Density Poly Ethylene (LDPE),  for instance, are not suitable, even though listed as good to fair, because the butane leaches out the constitutes, so they will end up in the meds.

They list copper as fair, not because the butane attacks it, but because of sulfur compounds and water that may be present in the butane, which form sulfuric acid and attacks the copper.  Dry low sulfur butane doesn’t present the same issues, but copper columns have to be kept meticulously clean of oxides, as for instance, welding copper without adequate respiratory protection, produces a medical condition known as fume fever.  If you do not have the time or inclination to keep the extraction column pristine, glass or stainless is a better choice.

Poly Propylene (PP), Poly Vinylidene  Fluoride (PVDF), Polytetrafluorethylene (PTFE=Teflon), are listed as excellent, and High Density Poly Ethylene (HDPE), Ultra High Molecular Weight Poly Ethylene (UHMW), or Cross Linked Poly Ethylene (XLPE) may be, but are not listed.

Glass and borosilicate (Pyrex) work well, as does 300 series stainless steel.  Neither are dirt cheap, but our local cost for borosilicate columns from the local scientific glass blower is only a buck an inch, plus five bucks to flare one end and close to an orifice on the other end.  1″ Stainless schedule 10 pipe was only $6.20 a foot, last time I checked, but prices vary considerably, so you should check local sources for pricing.

I don’t recommend single pass columns with a larger ID than 1″, as extraction efficiency drops rapidly above that size.  Primarily because the material near the injection end is inadequately wetted, and because the larger the column, the easier it is for the butane to just find an easy route through, and continue to follow it.

The absolutely cheapest stainless column that I’ve found is one made from a stainless turkey baster from Bed,Bath, and Beyond for $7.99.  Throw away the bulb and pull the press fitted needle out of the threaded adaptor, and you are good to go.

I’ve made a number out of copper, usually with a union near the injection end, so that it could be easily opened and cleaned.  I also made a copper one with a can holder at the top, using a contractors size caulking gun, and my first experiments with pressurized butane extraction, were in a copper test sled.

In the latter case, we also added vibration and as we try to use free donated material where at all possible, I draw your attention to the gold plated personal vibrator used for that action and give thanks to the donor, whom wishes to remain anonymous.

A stainless column can be made by screwing a cap on one end and screw radiator clamping a double coffee filter over the other end.  Drill a 1/8″ hole in the cap for the butane nozzle, and after thoroughly cleaning the insides by washing out with alcohol and boiling in hot soapy water, it is ready to go.

You can also stick a one hole Neoprene cork in the top of the column, instead of using a cap.  It works well enough, though more sensitive to blowouts.

We have our borosilicate columns made and some development was required to stop breaking them in cold wet weather.  What was required to stop spalling off conchoidal divots from the injection port in frigid weather, was to make the closed end a smooth even radius of uniform thickness, so that stresses from uneven expansion and contraction were not an issue.  You also need to insure that the column is annealed after forming, to relieve all residual stresses.

We add a flare to the ends of our borosilicate columns, to make filter retention easier, so as to reduce blowouts.

A blowout, is where the filter at the end of the column ruptures and blows the column contents into your collection vessel, or the filter blows off entirely, doing the same thing, or when using a cork in the top, it blows out during injection.

You can guard against filter rupture, by backing the coffee filter with stainless mesh, or cloth.

Preventing a blow off gets trickier with glass tubes, in that you can’t just crank down harder on the radiator clamp, without breaking the glass.  Alternatives that work better with glass, are twine wraps, zip locks, or rubber bands.  We mostly use rubber bands, and stretch them tight.

Column Loading:

When loading the material in the tube, we use a wooden dowel to keep it uniformly and firmly, but not tightly packed.  A dowel close to the ID of your column will make even packing easier.

Before loading the tube, we wad up a coffee filter and stuff it in the injection port end, to diffuse the butane as it enters and so that no plant material blow back out into our extraction, should for any reason we need to release butane pressure in the middle of the process.

We cut the top out of a water bottle to use as a funnel, and pack the material as we load it, stopping about every foot to compact.  When the column is full of plant material, we double a coffee filter over the end, and then cover that with a cloth patch, securing both with multiple tight wraps of a heavy weight rubber band.

We also scissor trim away all extra filter material, so as to minimize the oil soaked up during the process. I find that if I am careful removing the filter after an extraction, that I can reuse it multiple times, so as to further minimize losses.  We also wash out our filters in alcohol, to recover any essential oils soaked into them.

Skunk pharm use of a column is common general practice, though our collection and processing techniques deviate from the norm. We simply support the column full of pulverized plant material over a collection vessel and inject butane through the top port in the column, and let gravity carry it through the column.

As the butane passes through the material in the column, it dissolves the trichomes, and conveys them out the end of the column, into the collection vessel.  The butane subsequently evaporates off, it leaves the extracted cannabis oil behind.

When the stream of solvent running out of the bottom runs clear, we cease injecting butane and insert a basket ball pump needle into the injection hole and blow out any remaining liquid. A modified butane can nozzle adapter will adapt the needle to seal the hole.

Examination with a microscope will tell you when the trichomes have been dissolved away, and looks like wet hairs lying down, with the capitate heads missing.  Our average yield at this point was around 17 to 18% by weight, but we’ve yielded up to 21.6% by dumping the column, repacking it, and making a second run.

This second run will be less heady, and of lower viscosity, with more sedative properties, so we keep it separate from the first.

Collection vessels:

How we are going to use the oil, to a large degree dictates how we collect it, so lets look at some of the methods we’ve found effective.

Pyrex Pie Plate:

The first that I tried, was collecting in a 10″ Pyrex pie plate, sitting in a larger Pyrex dish full of hot tap water.  That works well and the key is the hot water that it sits in, in at least this neck of the Pacific NW rain forest, where we often have high humidity.  If we don’t set it in hot water, ice forms at the edge of the evaporation pool, adding considerable water to the mixture.

The hot water also rapidly boils off the butane, until all of it visibly gone, although some remains un-purged and in solution with the oil.  Techniques for purging the remaining material vary, so we will cover those steps as a separate issue.

This technique is suitable for any process, with certain precautions and subsequent processing.

Stainless Bain Marie:

Even better in this land of the midnight rain, is a deep stainless bain marie container, sitting in a hot water bath.  The deep vessel fills with butane fumes, which floats away the atmosphere, so that no moisture laden atmosphere is anywhere near the evaporation line of the butane.  That is how we processed most of our oil, when using single pass columns.

The real advantages to using this type of collection, are that it can be wiped dry on the outside and the pot set directly into a hot oil pot for a rapid purge and decarboxylation, followed by formulation in the same stainless vessel, so that nothing is lost to films left behind in transfer pots.  We have the tare marked on each of them, so that we can weigh the material while still in that pot, to establish yield, and the quantities for the rest of the ingredients.

This system works well for decarboxylated and formulated meds, but presents a challenge to remove the oil afterwards, if you are not, and has less surface area for evaporation if you aren’t planning to hot purge or wash it out with alcohol and do thin film vacuum purging.  Absolutely the best method we’ve found overall, subject to the above limitations.


Butane is relatively easy to purge from cannabis oleoresins or concretes, as it has a boiling point of around -.5C/31.5F, or right about the freezing point of water.  Given enough time just sitting around, it will purge below our 5000 ppm smell sensory threshold, and even our far more acute sense of taste, either of which is a small percentage of the 658, 000 ppm, that the MSDS LD-50 tells us it took to asphyxiate 50% of the test rats in 4 hours.

We can speed up that purge, by using a dish with a large surface area, relative to the depth of the pool of oil.  Usually small extractions, so as to keep the pool depth thin, are the easiest to purge.

Typically, the thin film is scrapped and stirred periodically, to speed up the process, and a flame may periodically be lightly run over the surface, to warm it and determine if the bubbles exiting are butane and terpenes, or CO2.  Some care needed here, as THC, CBD, and CBN are di-terpene alcohols, and are flammable themselves, as are the other terpenes present.

Air movement over the pool speeds up evaporation, by whisking away the saturated boundary layer and providing the extra energy for the molecules of butane to escape the surface of the oil, as it is ricocheting about in the pool.  Care must be exercised here, as any dust or lint in the air will end up in the oil, so usually a cheese cloth or similar porous cover is placed over it, before blowing over the top with a fan.

We can also speed it up with the application of heat.  Any heat will speed up the evaporation, and one line of thought is to keep the heat low and around 60C/140F, using a hot pad after the hot water bath and scraping and popping any bubbles with a razor blade.  A typical purge might take an hour and provides maximum terpene retention.

When adding bottom heat, you can also add a loose fitting lid, which will speed up the purging and keep out lint and dust.

For a faster purge, the temperature can be raised to above the melting point of the cannabis essential oils, or around 82C/180F, to give the butane molecules maximum mobility.

Instead of heat, vacuum may be applied to speed up the purge process.  That is the process that we use when we wish to maintain the cannabinoids in their carboxylic acid forms.

In thin film vacuum purging, we place about an 3/16″ of the oil in a 6″ Pyrex Petri dish, and place that in a vacuum chamber, which also contains a hot plate.  That allows us to manipulate both the temperature and atmospheric pressure, so that we can achieve boiling at very low, or even ambient temperatures.

While we use 180F to vacuum purge a raw oleoresin, adding heat isn’t necessary when thin film vacuum purging raw oleoresins redissolved in ethanol.  The alcohol will boil away under 28.5″Hg at ambient temperatures, as will the water that is left behind, even without adding any heat.

For our oral and topical meds, we exclusively used the bain marie collection vessel, and simply wiped the water off the outside, following the hot water purge, and set it in an electric fondue pot full of hot 121C/250F Canola oil.

The residual butane will boil off first, exiting in larger, multi sized bubbles, followed by the smaller equally sized CO2 bubbles from decarboxylation.

Depending on the use, we remove it from the hot oil when the bubble activity suddenly slacks dramatically off, indicating the 70% peak of the decarboxylation curve, or when it becomes quiescent, if we are looking for maximum sedative effect.

Hot oil Pots:

We use electric fondue pots for decarboxylation and I prefer the Quisinart, for their sensitive controls and narrow dead band.  We also have a couple of Rivals, which work well too, but whose controls aren’t as sensitive.

Some fry cookers may have sensitive enough controls, but most are designed to primarily run at 375F, and lack control sensitivity, as well as have a large dead band at 250F.

It is important to make sure that the container is sitting on something that suspends it up off the bottom of the oil pot, to eliminate direct transfer hotspots. We keep several jar lid rings in the bottom of our electric fondue pots for that purpose.

We never trust any controls however, and use a good mercury lab thermometer, a digital, or an infra red optical pyrometer to establish and control temperatures.

Thermos extraction:

Thermos extraction is a technique allowing an extended soak period at atmospheric pressure.  At sea level, n-Butane boils at approximately -0.5C/31.5F, so unless the local ambient temperature happens to be under that temperature, the butane will warm up enough to return to its gaseous state.

In thermos extraction, the prepared material is loaded into a stainless steel thermos bottle and frozen before having pre-chilled butane added.  The thermos acts as a Dewar to keep the butane temperature low enough to keep it in its liquid state.

Dropping the temperature will of course also slow down the extraction rate, so the resident soak time must be increased to compensate.

An advantage of keeping the temperatures low, is that it allows you to run fresher material, as the water will be tied up in the form of ice.

Butane has the very slight water solubility of 0.0325 vol/vol, or about 32 milliliters per liter.  That means if there is any water available, some of it will come along and bring with it undesirable water solubles, such as chlorophyll.

Tying the water up as ice, allows a longer soak resident time, without picking up those water solubles.  Operating at 50F outside temperatures locally, an optical pyrometer showed the butane in the thermos to hover around +8.7F, with mild bubbling action and minimal loss of liquid.

Because of the low operating temperature, you can run either fresh frozen or dried material equally well and can therefore control a wide range of flavors, by simply controlling the pre extraction state of drying, and evaporation of aromatic terpenes.

A fully cured material will produce hashy tasting oil, and fresh material will produce floral oils, and the rest of the flavors will be in between.  The flavors besides cannabinoids, are the lighter mono and sesquiterpenes, which are the aromatic alcohols, phenols, ketones, aldehides, and esters.

Equipment required for this process are minimal.  I scored a gorgeous little stainless steel thermos at the local Goodwill for $4.99 and my only alteration was to drill three holes in the cap.  One to fit a lighter butane can nozzle, and a couple to allow venting during injection.  I tossed the inner lid, as the gasket was unsuitable for butane.

After soaking one hour, we pour the butane through a strainer suspended over a bain marie catch vessel, but we also subsequently winterize, so if you aren’t going to, you can rubber band a coffee filter over the opening and dump through that.

A second soak in chilled butane may be used to extract any remaining essential oils.  Jump, one of the developers of the process, reports using a 30 minute first soak, and a 2 hour second soak, with pictures showing pristine quality from both extractions.

Once in the catch vessel, the extract can be purged any number of different ways, like any other BHO extraction.

Notice in this case, we broke up the buds and removed the stems in a harvest box, which we subsequently harvested the kif out of for our pipe while standing around.



616 responses to this post.

  1. Hey GW,
    What about butanol ? It’s allot safer! and would it be possible winterize in
    that solution?

  2. Posted by Waleed on March 1, 2014 at 1:28 PM

    Hey GW, i’ve been trying to find a good amount on information on thermos extractions ive been reading everywhere but no one seems to give a good detailed explanation of soak times, i currently associate with a couple dispensaries and ive been trying to increase yields i have been using open tube for 3 years and would like to switch to thermos before i get my closed tube. My question is how long can you soak i understand you have said that your friend does 30 min and 2 hour soaks with both being pristine extractions. which is great but im curious if you do soak for lets say 4-6 hours could you still get pristine quality and yield more? (also would you i be pulling more fats cause of the soak?). I am using grade a trim after about 5 days of drying(small stem snap). using open tube i get yellow, amber, light colored high quality extracts in general. not trying to gloat as i have copied the tec from others(including yourself) and the growers have done everything for me i just would like to know if that color would darken for longer soak times… I also am curious if you have heard of dewaxing it is like winterization but using butane i havnt read anything on here about it and would like to share the information with you if you havnt heard of it(i was assuming you are aware but did not post it on here cause it is a lot more dangerous.) i dont get why people like adding a second solvent when u can remove the fats with the solvent you are using to extract before the butane evaporates, much easier imo and you dont have to use another solvent that boils at a much higher temp.

    • We encourage everyone to move to a closed loop system. Its extremely dangerous to blast. One recent explosion was determined to have originated from a neighbor using their toaster. You could do everything right and a piece of toast might ruin your lifetime.

  3. Posted by John nichols on March 1, 2014 at 6:47 AM

    Is there a way to (clean) the bho so that it has a nice golden color instead of a pine tar look?

  4. Posted by joe rodriguez on February 28, 2014 at 2:06 PM

    Couldnt you blow into a parchment paper on silicone pad under bubby hot water til evaporation, vac for a few, flatten to square, then vac for 12-14hours? on 81-84 degrees on the hot plate, decarbing and purging all the terpenes out? But how do you know what heat for wax and shatter?

  5. Hey gray..

    Running a closed loop system, an active one. Coming across residue.. Just trying to distill my CP n-tane. A tire smelling amber colored shit. I am running an appion with this system. Is it possible to pull this residue from the appion? Is my n tane from airgas just dirty? I’ve distilled it 3 times with the same residue. Now I’m runnig a passive recovery to see if it’s still there. Thoughts, opinions?

  6. Posted by Joe C on February 24, 2014 at 2:56 AM

    Hi Skunk, Ive read in a few places before stumbling on your awesome site that dehydrating or putting bud in the oven before is better for BHO extraction… i plan to winterize but not decarboxylate as the end product will be vaporized… What are your thoughts on the drying pre extraction? & any other suggestions greatly apprecited !

  7.–Its a polypropylene cap with a silicone seal that screws onto mason jars, wide or regular, spill proof. works AWESOME for mason soaks, self filters to a decent degree for winterizers, use mesh if just purging. That link goes to the ebay sellers page for the caps. Stay safe

    Join the Skunk Pharm and their friends today.

  9. Posted by thrag on January 23, 2014 at 8:00 PM

    I use an empty rum bottle with 3 caps. 1 for injection 1 for extraction and 1 for straining. The injection cap has 2 holes. 1 in the center which is tapered for the nozzle fit, and 1 at the perimeter for pressure relief. The straining cap has a series of small holes drilled over the entire top and fitted with a coffee filter section. Everything (weed, bottle and gas) is frozen before starting. I simply fill the bottle 3/4 full of dry finely chopped weed and add butane until weed is covered. I then switch to the extraction cap which has been unaltered. This cap will prevent the butane from gassing off after it reaches its partial pressure equilibrium. I leave it sit for 20 minutes. I then CAREFULLY AND SLOWLY remove the cap from the bottle relieving the gas pressure that has built up, and place the filtering cap on the bottle and pour off into a pyrex bowl. Simple and cheap.

  10. Posted by Colomex510 on January 17, 2014 at 1:18 PM

    Nice feed bro… What u think of my tech? If u dntund reading bt I blast on to a little squared Pyrex waterbath at 120 f for 3 hours then I let it heat purge at 100 f for 48 hrs throw in to my chamber turn my vac on 29 ppm for 72hrs at 100 f n here’s where I have Trouble it becomes very stable n I have hard time scraping off any suggestions?

    • You will get better aromatics if you throw it in the vacuum chamber as soon as the visible butane is gone, at 115F and -29.5″ Hg until the solvent bubbles cease.

      If you warm the dish up some, it will scrape easier.

  11. Posted by keith on January 11, 2014 at 5:04 AM

    My oil is so sticky I can’t even work with,what can I do to make it more dry?

  12. Posted by cory on January 10, 2014 at 9:22 AM

    I’ve managed to purge to a shatter but can’t seem to get it out of the pyrex vessel without it shattering into hash-dust. Any tricks to this? Prying/scraping tools? Temperatures? Perhaps my thin layer is too thin?

  13. Posted by Chris on January 4, 2014 at 4:20 PM

    Due to a static spark my butane collection pot caught fire . I have a lot! Of oil in it but I was forced to use a ABC fire extinguisher. Will I be able to recover my oil back? I was thinking maybe I can dissolve it in ethanol and try to drop it out of solution with cold? What is your idea? There’s just no way? Or with effort and time yes

  14. Posted by Aardvark on December 30, 2013 at 7:29 PM

    Hey GW, thanks again for keeping this thread fresh, even after evolving on to the The Mk IVA Phoenix Terpenator. I am assembling my own closed system and decided to revisit back to the basics and see here that you recommend a column no larger than 1″; however, the Terpinator has a 4″ capacity. Is the 1″ column constraint only a factor when using the open system?

    AirGas quoted me $238 for 23.1 pounds of 99% N-Butane (plus $150 shipping & tank fee), but I also saw here that it is a controlled item, so it may be hard to obtain. What is the best way to “clean” the canned Colibri-type from cans? I already have a few lab-grade stainless tanks for reusing the Butane. Is there a carbon/silica cartridge I can use to filter out the water content as well as boiling off the Propane? Would an automotive refrigerant dryer cartridge help?


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  16. Posted by Dr. SexPot on December 29, 2013 at 9:16 AM

    Thank you Pharma-Wolf

    In your vast knowledge of canna/Chemistry what base product (method of extraction) should I be using for edibles that are geared towards recreational use? Conversely: what method (is it different then above) for a edible geared towards medicinal edables?

    • I use butane for both. I extract using more heat in the recovery pot when making decarboxylated oil for medibles, and no heat to keep it in carboxylic acid form when extraction for vaporization.

  17. Posted by Matt on December 23, 2013 at 10:24 PM

    Thanks for the wealth of information. You do amazing work.
    I was wondering if you could use a glass mason jar or stainless steel pot instead of a thermos?

  18. Posted by MadHasher on December 19, 2013 at 7:47 PM

    Merry Christmas to all you on the SkunkPharm Team, hope that you all are having an awesome holiday season! I was wondering a few things about the Thermos extraction, I am planning to do it following your instructions, but using a 145u sieve to 120u second sieve dry ice extracted kief as my starting material. I have been getting 2 ounces pr lb of decent 3/4 sugar trim and 1/4 big leaf after following a lot of your info I dried and froze the material for 48 hrs before tumbling, using a 2-1 at least ratio of dry ice to material weight I tumbled for 2 mins, in return my I got on clock work a 53-58 g’s to lb of material, which in turn got 45-50 g’s off the second sieve with dry ice through the 120u (this was done directly after the initial first sieve while still cold transferred from the 145u to 120u drum for filtration). I will be breaking down the 120u into full melt kief, all the left overs from that as well as the initial 120u leftovers I plan to put through the thermos extraction which I will subsequently winterize as you suggest. While considering what is my starting material, my questions are:

    What ratio of butane to material should I use?

    Would you suggest a longer and/or multiple soaks?
    Is there a specific type of butane that you would use?
    And one slightly off subject question, is it possible to turn polished “absolute” to “wax” or are some components of the “wax” equation filtered out once the polishing process of the absolute has been done?

    Thanks so much for your time, and please take your time, enjoy your holidays, thank you so much for all your hard work and dedication to the giving of this information. Bless

    • No ratio, we lightly pack the thermos 3/4 full and fill the rest of the way with butane.

      We use one soak if we are making it to vaporize ourselves and one thirty minute soak, followed by an hour and a half soak if we are going for bragging rights.

  19. Posted by Josh on December 14, 2013 at 1:49 PM

    My mother has been diagnosed with cancer, it has been close to 8 to 9 months now. e want to try some oil to see if that will help her. I saw that in your article it states that both THC and THCA have medicinal properties. In my mother’s case, would THC be better? Also you state that heating the BHO to activate the THC will evaporate some of the terpines. Am I better off making the oil with alcohol? Thanks in advance!

    • CBD may play as much or even a stonger role in cancer treatment, than THC.

      It is easy to extract all of the terpenes, by any number of different methods, so holding on to the monoterpenes during purge is the challenge. It is easier to extract the oil with butane, but without significantly lowering extraction temperatures, you will end up with waxes that you have to winterize with alcohol to remove.

      Alcohol doesn’t extract the non polar plant waxes, but it grabs the water solubles and chlorophyll, so the process has to be done frozen and more carefully controlled.

      Before focusing unduly on the terpenes, take a look at the medicinal properties of the individual monoterpenes present, and consider what effect they may have on your mom’s cancer treatment.

  20. I have a bunch of fresh flowers (non decarboxylated, uncured, non frozen) that I ran once through a butane extraction via a glass tube. After looking at the material under a microscope there is still a significant amount of trichomes on the material. I have access to 75%, 151 proof grain alcohol and 99% isopropyl alcohol. I was wondering which solvent/method (temperature, pressure, time, agitation) you would suggest I use to have a final product that can be vaporized?

  21. I have a bunch of fresh flowers I processed one time through a butane extraction via a glass tube but still have significant trhricomes (when looking at it under a microscope) on the material. I have access to 75%, 151 proof grain alcohol and 99% isopropyl alcohol. What would be the better option/ method (temperature, pressure, time of agitation) to obtain a product that can be vaporized?

    • The 99% will produce a superior extraction for vaporization.

      • Thanks, I did a combined 1st and 2nd wash with the 99% in a mason jar and then filtered it through a strainer.
        I am refreezing the material because it appears to still have at least 30% of its trichomes left ( I am planning to cook that into a coconut oil for oral consumption and topical rubs).
        Since I didn’t have enough ISO to do all the material I have left the butane washed material frozen until I can obtain more 99% and get back to location where the freezer is.
        I didn’t have the time to run the ISO extractions I did do, through a coffee filter yet, so I also placed the mason jar with the 99% extractions in the freezer.
        I did test dry some of the yield from the ISO extractions in a pyrex dish (1 dish not run through the coffee filter and 1 dish with it ran through the coffee filter), and let it dry. It turned into a green oil like material. I am guessing this is why you want to do the heated water bath after an ISO extraction? Is that what makes it into a high quality vaporization extract?
        I appreciate the work you do. I myself have been running tests long before I found you, using all my knowledge from Organic Chemistry so thank you for adding your knowledge. It is most helpful to have someone whose has ran, or has data from running an experiment I have not ran myself.
        I do have one last question for you. Do you believe I need to take any steps before cooking the left over material that is frozen and has been through the 1 BHO extraction and 2 ISO bath extractions?

        • Please elaboborate on your Iso process.

          I’m surprised that after a BHO and two ISO extractions, that there is enough left to make a forth extraction cost effective.

          • Posted by Asmodeus on January 14, 2014 at 5:45 PM

            I did a bho for first, iso for second and tried another iso for a third and ended up with a blackish tar that smelled like grass–not the good kind–

  22. Posted by grrrld on December 9, 2013 at 6:24 PM

    been making bho both for vaping and edibles. been using the same material for both. column holds ~65 grams. not the freshest material, but it was cheap. decarbed material (2hrs at 200 degrees) has consistently yielded ~6g, whereas the other yields ~10g. any ideas as to why decarbing is reducing the yield? and would it be more productive to decarb at the end of the process?

  23. Posted by Lady Stiltz on December 9, 2013 at 2:38 AM

    Ok just trying to get this right from the get go. I’m using fresh frozen bud in one run and the left over trim in another. Planning to use the thermos method, using the end product in an oil rig. Question is I plan to soak and dump twice into a Pyrex dish in a hot water bath. I want to winterize, so post bubble stopping do I then add the alcohol direct to the Pyrex? And do I need to do anything additional before throwing it in the vac purger to get rid of the alcohol or will the vac do that for me? Sorry that is where I am to get lost. Great information, thanks for helping keep everyone informed and safe!

  24. Posted by Sam Stroup on December 7, 2013 at 3:29 PM

    Oral consumption of hash oil has lots of varying opinions on the correct way to perform such a task and I was wondering if you could help clear up some of the questions I have about it. There seems a consensus that whatever method of administration you choose the THCA must first be decarboxylated into THC. Where the most variation in opinions occurs in wether this now active THC needs a solvent such as ethanol, or and fat based solvent for efficient absorbtion in the intestines or if the decarboxylated [butane] hash oil could just simply be swallowed. Any help clearing this up would be greatly appreciated.
    Thanks in advance

    • THCA and THC both have medical properties, so it depends on what you are treating, as to whether it has to be decarboxylated. Cannabis oil has to be decarboxylated to be orally active at the CB-1 receptors, but only because of the blood brain barrier, which isn’t an issue for the immune systems CB-2 receptors.

      Cannabis oil will absorb all by itself, but if you take it with alcohol or a fat, they will tie up the liver processing them, so as to leave the cannabinoids in our system longer.

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  26. Posted by zungguzungguguzungguzeng on December 1, 2013 at 9:18 AM

    Hi, first of all thanks for such detailed explanations and for the engagement with the community, you are amazing!
    That said I’m trying to do my first extraction with the thermos method but I’ve got some doubts I’m hoping you could help me with.
    First of all, the material would be fresh trimmings that I conserved in my freezer in tupperware, so while it was pretty much sealed since it was not packed very tightly or to the brim there’s definitely some ice but just on the surface I guess, I red you recommend to let it thaw out until dry, pack in the thermos and re-freeze.. but if I already drilled the hole in the thermos won’t the ice just form again in it? Or even if it’s still intact if it’s not completely filled won’t the remaining air inside form a film of ice on top as it happened with the tupperware? Mainly I guess I’m asking what’s the adverse effect of the ice and if it’s just a film on top can I just scrape it away and be cool?
    Also, how much should I pack said thermos as rule of thumb for a good soak?
    I also red in the comments of people doing the soak while putting the thermos in a basin of ice and in your photo you just left it outside with a towel over it, couldn’t I just put it back in the freezer? Because of the low temperature the butane should remain liquid and not be risky, so what’s the downside? Lower temperature just means longer soaking time?

    • The issue with ice covering the trichomes is of course that the butane doesn’t have access to the resin. That is why it is important to seal the material before freezing.

      Whatever your process, you need to remove the ice before extracting. Ostensibly you could sublimate it away under vacuum as well.

      We pack the thermos about 3/4 full when pressed firmly with thumb pressure, and submerge it in about an inch of butane.

      I don’t recommend putting an open container of butane in a freezer. There are some examples on line of folks who thought they could get away with and were wrong.

  27. GREAT SITE! I love how much there is to learn! Quick question,
    When trying to make a winterized extract as the end objective, is it necessary to hot-water or vacuum purge the butane from the extraction mixture before adding the ethanol? I have seen individuals simply pour the ethanol into the butane/extraction mixture while the butane is still liquid, and a rapid bubbling ensues.Is this a safe way to purge the butane, or is more purging needed?

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  29. Posted by C4h10 on November 24, 2013 at 9:52 PM

    Hello GW, When I vacuume purge I normally run my vac chamber at about 110f and about -27hg (can’t seem to get this pump to go all the way to -30) normally I purged until all the bubbles stop rising to the top wich is around 6 to 8 hours. Recently I’ve tryed flipping my slab over and purging again for a few more hours. The thing that’s confusing me is that every time I flip the slab over it seems to bubble up against even after a few flips. Could it actually be that every time I’m pulling more butane out? Or is it just air getting trapped in the concentrate? Do I need more vacuume or heat? Thanks.

    • What altitude are you at? You can only hit 29.92 inches at sea level and by 2000 feet elevation, barometric pressure is only around 27″.

      If you will raise the temperature to about 115F and stop purging when the larger irregular bubbles cease, you will be good. Carboxylic acid will continue to release smaller fizzy bubbles as a function of decarboxylating.

  30. Posted by Gbroque on November 16, 2013 at 9:09 PM

    Does one need a solvent safe vacuum pump for cold boiling a winterized alcohol solution? If the answer is yes, does one need a solvent safe pump for use with a Büchner funnel?

    • You need either a solvent safe pump, or a cold trap to cold boil alcohol. You can get a small solvent safe pump, and switch to it after pulling down the chamber with a larger conventional pump.

      You can also make do by changing the pump oil frequently, if if the level gets too high, or the color changes.

      A Buchner funnel is a less severe application and it isn’t as long, but eventually you end up with the same problem. We picked up a military surplus MASH pump for filtration.

    • Skunk Pharm is spot on. A standard, oil-sealed rotary vane pump will quickly be trashed when used for solvent extraction. A dry ice trap is a solid, cost-effective accessory that will also allow for reuse of Butane. Dealing with cry ice can be a hassle and a safety hazard so do your research. Refrigerated traps tend to be prohibitively expensive for all but full-scale producers. We recommend a chemical duty membrane pump. You still have the flexibility of using a fore-line trap for Butane reuse but you don’t need to in order to protect your pump.

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  32. […] to extract the frozen material? Can you explain this process please fade? Here is how we do it. We cut the fresh colas up into about 1/4" pieces and pack into a thermos, which we put a lid […]

  33. Posted by Andy Sanchez on November 7, 2013 at 1:51 PM

    can any regular refrigerant work?
    I.e r22, r12 ,r134a ,r407c, r404a ,r410a.

  34. Posted by Eric on November 1, 2013 at 4:50 PM

    What’s the best way to preserve wax, and to save potency

  35. Posted by Jamie on October 28, 2013 at 12:31 PM

    I’ve been looking to buy a vacuum chamber and have heard good things about the vac-it pro. I was able to find it on ebay about two weeks ago but didn’t buy it. Now when I look on the ebay page it doesn’t show that he’s selling anything. I tried the website ( and that didn’t work. Does anyone know if vac-it-pros are still being sold?

    • Sorry, no. We’ve never used one and haven’t kept track of them.

    • Posted by Geoff on October 30, 2013 at 9:04 AM

      I noticed the same thing. I don’t know where to get a vac it pro, but I ordered a similar chamber, the provac, off amazon. It is a bit more expensive, 160 with shipping, as opposed to the vac it pro, which I believe was 125 with shipping, but also has a few extra features, such as I rings around the joining parts to help provide a better seal. If you are interested I am happy to give you a more thorough review when it comes in the mail tommorrow. Just reply or email me at

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  37. Posted by Hydra Group on October 27, 2013 at 5:24 PM

    Hello GW and thanks for all the wonderful work you do for the community

    I have a 48″ stainless steel extraction tube 1/2 lb and packing and loading has been a major pain in the arse LoL I remember seeing a post about using some air thing to clear the tube out easily?? Aside from that any good tips on loading and unloading?? One person recommend to me to unpack right after running the BHO into the pyrex my concern is that after running the cans I see butane gas still coming out from the top and worried if I open the clamp and oring seal it will not be safe?? Would love to buy one of those MK automated systems when they become avail

    Any recommendations for “open style” extraction tubes for 1lb or more processing??

    • Packing a pound into an open column either makes it excessively long, or large in diameter. You could run 160 grams in a 1″ X 48″ tube, but it might be tough to unload, even with air pressure. When we were experimenting with 48″ columns, I used a 6′ electricians flexible drill bit to punch it out when stuck.

  38. Posted by Gbroque on October 24, 2013 at 11:21 PM

    Hello again…. I have a few questions about safety.

    I recently received some components of my extraction setup, namely a hot plate/electric griddle and a infrared thermometer. both came with warning labels, the electric plate cautioned about sparks and “risk of fire” presumably exacerbated with the presence of butane… the infrared thermometer warns against using on flammable materials… like butane… but everybody uses these thermometers while making bho!
    1) How can i maximize safety while using the hot plate?
    2) How can i safely use the thermometer?

    On another note, i was wondering why people use hot water baths/double boilers to purge instead of just low heat on the griddle, if its because of the griddle not going low enough, would the use of a light dimmer help cut electrical flow to the griddle, reducing temp?

  39. Posted by Kyle on October 24, 2013 at 9:56 AM

    I could use some help. I did a run, about 12 ounces or so, into a 8 by 8 pyrex dish. Heat was at 120 but I think because I used a smaller dish the tane made it cool down a lot because it piled ontop of each other. However, after blasting outside and it evaporating I brought it inside. Scraped it up and put it on parchment and into my vacuum chamber on my griddle. My griddle is a black and decker that is 4 years old. The temp settings don’t do much. I’ll turn it until it barely kicks on, the lowest temp and it’ll shoot up to 170 then turn off and won’t turn on until it’s close to 100 again. I put a pizza stone under my chamber to help with heat. It’s been going for 9 hours at full vac since I added the pizza stone, prior to that about 24 hours at full vac. Still hasn’t waxed up. I’m wondering if it’s because my griddle is basically flash heating the entire time but the pizza stone kinda prevents that to an extent so I just don’t know. >.<

  40. Posted by Alex R on October 21, 2013 at 2:07 PM

    Hey Greywolf, I have read many of your posts on this site and various forums and appreciate you informing the public with safer and effective techniques. I have been making BHO for quite some time now and I still struggle with one thing. My question for you is when purging by using heat from approximately 130-140F, what are the tell tale signs that the oil is ready to be scraped? How can you tell that all the butane has properly been purged out enough for the product to be safely vaporized?
    One last question is I have a batch of oil that would leave a very strange residue, so I repurged it at temps that must have gotten rid of any remaining butane, but the oil continued to leave a strange residue. Is the residue most likely harmless? Any information on the matter would be greatly appreciated.

  41. the tube is 10 1/2 in long and about 2in across(looks very similar to a tube of caulk or silicone, for a comparison) the packing wasn’t too tight (i use a wooden dowel about 3/8 in size and do not force it to pack tightly ,basically i just use the weight of the dowel the pack it. as far as material(i am a medicinal grower/caregiver so have decent material to work with) but i have been letting it dry and chopping it up with scissors to a joint roll-able consistency (maybe not that fine but close) i have not inspected with microscope, going to start doing that.
    thanks for the help btw
    a friend suggested i put some paper beside be when i am making my product and to quickly let a few drops onto the pape the quickly back to the pyrex dish , he said if u see no golden color it done if u sitll got color keep on going with ur solvent. what do u think about this idea? thank u again i so wish i could get into some of the studies u teach

    • I recommend a smaller ID tube, no larger than about 1″. I liked my 1″ X 36″ tubes for that purpose.
      Get around a 3/4″ packing dowel, for the 1″ tube.
      Push down firmly on the material, until it stops moving and then quit. Pack several times in the course of loading the column, to keep it even.
      I stick my finger in the stream and check it for sticky between my finger and thumb.

      • i was thinking the same, a bigger dowel would probably ensure a more evenly packed tube too as far as my larger tube goes. thanks bro! i just harvested some pretty frosty goodness so i am drying it out as we speak. it will take probably a few-some days depending on the wonderful Michigan weather,but lately it has been cool and wet so i am redialing in my drying area. i am thinking i may just stick with my turkey baster for some runs until i can get better with my returns ? at least so i don’t go through so much material lol :) , i have been reading more about the turpinator u built and the schematics(sorry if i miss spelled) how are the returns with that beautiful monstrosity? :) i hope ur having a great Sunday GW, watching some football and relaxing

        • Averaging just over 20% on prime bud and about half that on trim.


          • thanks again. i gat amother problem too. i did the routine same as before, i had approx 1.8g i vac it down and placed it on the griddle at about 150 degrees F for approx 2hours and 10 mins. i pulled it out lut it cool and it was like a syrup consistency? i contacted a acquaintance he said my pyrex plate may not have been hot enough and being the butane is so “cold, to say” it trapped moisture from like condensation or something? i has been siting for like 3 days and still no solidity. is this possible about the moisture thing? the plate temp was like the only thing i did not check before i started blasting. i did freeze the butane cans for like a hr befor i blasted and the were frosted over when done. maybe frost from can? when u hit it to the nail it crackles or sizzles a little sounds like if u ever had water in ur titanium nail and try to heat it , it will sizzle and crackle a little. please help GW . thank you my friend

          • If you heated it to 150F for two hours without being in a vacuum, you most likely have partially decarboxylated it, so it won’t turn to shatter.

            If it has water in it, it will crackle and fire dance. You might spread it thin on parchment and hit it with a heat gun, or use vacuum.

  42. Posted by cooper on October 15, 2013 at 2:03 PM

    i am new to extraction process i have did a few runs with flowers, however no matter how hard i try i cannot get my returns over 10-12% (12% if i am kicking ass that day lol) and most peeps i talk too on the net say they get like almost 20% on nug runs ? i have read quite a bit of ur work here u seen to be the most informative also on the other site forms too so here is what i have i have….. 2 nonbleached coffee filters, glass blasting tube along with the turkey baster tube (glass can hold about roughly 35g of semi-hard packed material,and of course u know what the turkey holds), and Lucienne butane. from their i do the pyrex dish with w/hot water bath underneath.(i am sure u smell what i’m stepping in now)…..but i do not freeze the butane or column will this make a difference? and can u give me any more pointers? please thanks you so much for the help and reply also thank you for taking the time to share ur work to ensure people get a good understanding on how to provide a safe medication

    • Yeah, we average about 20% yield by weight on prime bud, but have had as low as 5.7% and as high as 28.1%.

      How are you preparing and packing the material. What state of dry is it.

      How large an ID is the glass tube.

      Freezing the tube will improve quality, but will reduce extraction efficiency.

      Have you examined the left over material with a microscope, to see what is being left behind?

  43. Posted by Geoff on October 15, 2013 at 2:00 PM

    I’m trying to figure out what tube to buy and could use your input, the one I am most interested in is a 150g apx capacity tube with a 1.5″ diameter, possible bigger, no more than 2″. The other is a little more expensive but 1.1/4″ diameter, with a 200g apx capacity.
    Also wondering about how best to purge an ethanol winterized solution, with shatter being the goal, and time being an issue. I read cold boil can take a while. Given that I want it to be a shatterific as possible, I presume that means a minimal amount of decarboxilation in the purging process?

    • Anything larger than about 1″ ID is hard to pack evenly enough that the butane doesn’t just find an easy way out. I used a 1″ X 36″ for efficiency and ease of packing and unpacking, which holds around 115/120 grams of 10 mesh prime bud.

  44. Hello,
    I use the stainless steel thermos with kif and butane (all freezer chilled to 0f) to extract my bho. Normally, I put the thermos in a 1 gallon plastic pitcher of ice to keep everything cool for longer, and stir the contents with a long kitchen knife every so often to keep refreshing the boundary layer to enhance the extraction speed. I have kept the contents cold for up to 2 1/2 hours before dumping and filtering.

    It occurs to me that the process could be improved with the addition of vibration. As I do my extraction outside in the open, and butane vapor pooling isn’t a problem, especially with the 0f temperature of the butane minimizing evaporation.

    What I am contemplating using is an inexpensive ultrasonic (42,000 cycles, I believe) jewelry cleaner such as the one in this link …..

    Have you any experience with this? Do you think the boundary layer would be effectively moved? If you think this idea has some merit, would you vibrate constantly, or every few minutes, or do you see problems?

    Thanks in advance


  45. Posted by tom on October 9, 2013 at 5:11 PM

    I am going to be making oil for my first time this weekend so i just wanted to make sure i had all the info i can get. how do you make it so that your oil comes out in the “shatter” form or the Honeycomb form. Is this something that is done during the purging process?

    • Oil starts out in the shatter form unless you decarboxylate it with heat or retain solvent.

      We get the best results reliably producing shatter, by using -29.5″ Hg vacuum and 115F until the solvent bubbles cease coming off.

  46. Posted by triple on October 9, 2013 at 3:53 PM

    Hi Sunkpharm, first off great site! I have spent hours scouring this site, as well as others, looking for an answer to a question i have:since both kiefing and bho extraction recover approximately the same amount of product from buds- say 20% return-and from my reading i see GW proposes a 60% or greater return on kief.
    Is one losing 8% yield [in this theoretical example] by pre kiefing the buds?
    Yet, at the same time, one is reducing the amount to be processed with butane by a factor of 5X.
    I am considering getting a Mark3a from specialized formulations with a 6″ column for kief as per your use mentioned above.Using kief rather than bud seems as though it would allow one to gain efficiency by using 1/5 the material…albeit with a corresponding lose in yield.An alternative may be using bud in a Bhogart 5lb model or equivalent. Or perhaps your own Mark V when it becomes available.I cannot find yield data for the Bhogart unit online and they have not returned queries regarding this matter as of yet.
    In the short term i am going to try the thermos method-would i get similar yields but in a longer time frame with the thermos method as compared to the Mark3a?
    Thanks so very much for all you do!

    • Assume there is about 20% potential by weight.

      You extract about 10% kifing, which leaves about 10% behind on the plant material. Kifing a higher percentage, starts to green the kif from leaf material.

      A 60% yield on that kif, would be a 6% overall yield.

      You might build a Mk II with a 3″ X 36″ column, you can process a couple pounds at a time.

      The automated Mk V prototype is in final assembly. I’ll post some updated pictures.

      The Terpenator should provide a higher yield than a thermos with a single processing.

  47. Posted by J444 on October 8, 2013 at 3:29 PM

    I want to make my own BHO for my O.PenVape. I refill it myself now with Tetra Labs Pure Gold but it is expensive at $30 per .5g. I am concerned about the consistency of the final product, Pure Gold is about as thick as honey. What is your BHO’s consistency and what oil if any can I add to it to so it will absorb through the wick and vaporize?

  48. Posted by cooper on October 8, 2013 at 10:56 AM

    i have a few question do you still check the site and update? i could really use the help as i am trying to learn for my patients. thanks

  49. Posted by Kyle on October 3, 2013 at 2:34 AM

    Hello, great research and read. I make my bho for vaporizing and I dehydrate my material at about 110 – 115 for a few hours. It comes out golden and whatnot but I need to increase my yield. What are some things that can be done to increase yield? Thanks in advance.

  50. Posted by korupt on September 26, 2013 at 12:00 AM

    So I did my 3rd and 4th run yesterday and I manage to increase the yeild 3-fold by using trapped butane and soaking my material and shaking. Since I use good grade hash I dont think long soking is a problem for me and I get a pretty decent clarity. My result looked something like: but I will post a pic or two when I’ve gotten my vac chamber.

    So with that experience, I got a few questions if someone has the time.

    1: Does long soaking pull out more impurities.
    2: What does long soaking in butane pull out.
    3: Will these supposed impurities go away with a hexane/saline wash?
    4: What is the smallest possible filter you could use? I’ve seen 0.2 micron mentioned a lot.

    Thanks in advance

    • If you soak long enough, you can pick up water and water solubles. Though non polar and generally considered immiscible in water, butane will absorb up to 32 ml/L if left long enough.

      It will never pull a dark green extract like a polar solvent will, but it will start to take on an electric green hue.

      Ostensibly they would be removed by a hexane/saline wash, but so will many of the monoterpenes getting rid of the hexane. It isn’t harsh like extracts heavy with chlorophyll, but the color is off putting to some folks.

      We use 25 micron to winterize and then filter down to 0.2 microns, using a syringe filter.

  51. Follow more of the Skunk Pharm Research llc team on Twitter @GrayWolf23

  52. Posted by Geoff on September 24, 2013 at 4:57 PM

    Hey, I have a few questions I was hoping you guys could answer for me. Sorry if I’m posting in the wrong section or my answers have already been covered.

    1) I see a variety of Vacuum pumps in use, single and 2 stage, as well as with different CFM ratings. I am willing to cash out on this most essential gear for a good one if I need too, but would rather spend as little as I need too. Is a single stage 1.5 CFM pump good enough to get the job done? For that matter, is there any advantage of a two stage pump other than noise level?

    2) I plan to follow your ethenol wash 48 hour freeze polishing process, do I still need to vacuum purge to good bho quality/at all my bho before I use this process? In other words, will the ethanol wash take care of the butane?

    Related ethanol wash questions:
    What is a safe way to store the ethanol mixture in the freezer
    How much ethanol will I need to use for say, an ounce of bho?

    3) as far as extraction tubes go, does the length matter? As far as I can tell, the longer the better, but I wanted an expert opinion.

    4) I have seen a lot of people hype about using a dehydrator to eliminate more chlorophyll, I want as gold and as pure a product as possible, without loosing too many cannabinoids along the way, is his the way to go? Is it as good worse or better than the decarboxilation w an oven you describe on this site?

    Thanks in advance, and I’ll take this opportunity to thank you all for sharing your research and insights on this site. It is very helpfull.

    • A 1.5 cfm single stage vacuum pump would get the job done, but a larger one would get it done lots quicker. We like our CPS VP6S single stage rotary vane pumps.

      Even a single stage pump can pull low enough to boil away the THC at room temperature, so no need for a double stage.
      The ethanol will remove the butane.

      Under an inch ID for an open column extraction, and much over about 36″ becomes a pain in the butt to unload. I made 12″, 24″, and 36″ lengths last time around, and the 36″ got used most, the 12″ second, and the 24″ hardly at all.

      Chlorophyll is not much of an issue with a non polar extraction and we freeze the material and the solvent for a polar extraction. Fully desiccated material will shed more chlorophyll than something in the 20/25% moisture content, because the water soluble chlorophyll binding proteins are also desiccated and less effective.

      I prefer to decarboxylate my oil in a 250F hot oil bath after extraction.


  53. Follow GrayWolf on twitter


  54. How crazy do you guys go on stem/leaf removal for fresh material to be frozen?

  55. I am looking at various glass BHO extraction tubes. I would like to get one that holds just enough high quality flowers to exhaust 1 can of butane, without wasting too much THC. Would you suggest a 28gram size 9 inches tall and 32mm diameter, or the 40 gram size which is 9 inches tall and 38mm in diameter.
    I am not expecting 100% in one can, of course …. 85-90% with 1 can is what I am looking for.
    Or are both of these sizes too large … there is a mini, which only holds 7-10 grams 7 inches by 19mm … it seems to me that this is too small to need a whole can of butane.

    I found the alcohol extraction class fascinating, and informative. And the lunch provided by Carla, was deliscious. Thanks for everything


    • I don’t recommend a single pass extraction tubes with an ID of larger than 1″. I like a 1″ X 12″ for one can extraction.

      • Posted by Geoff on October 14, 2013 at 1:08 PM

        What about for multiple can extractions? I’m looking into a 150g tube with a 1.5″ inner diameter, would that result in a profound drop in yield? Since it has a 150g capacity I would be running 5 cans of butane through it per load.

        • 1″ ID is about the largest tube size that we found to efficiently extract material in single pass columns. The loss depends on how carefully the tube was packed to keep the butane from just finding an easy way out.

    • Posted by Everett James on September 21, 2013 at 10:08 AM

      14-18 gram extraction tubes will yield the cleanest/most consistent trichome count, but will take longer to extract depending on your batch size. I’ve found 25-28 gram tubes to work a little better in terms of portioning out butane, as I average out 300mL (1 can) n-Butane per Oz of plant material per run through. Most head shops will carry glass or Boro tubes in half-Oz, Oz, 2-Oz, and, more uncommonly, 4-Oz sizes.

  56. I tried a butane in the ss thermos extraction with frozen kief and frozen butane. I put the thermos (like yours pictured) in a container of ice cubes, so I could extract for hours. What I found was that there was still plenty of undissolved thc in the (former) kief, after it dried. I ran a 2nd can of butane with the same setup, and after drying the remains, still saw plenty of thc.
    My question is do you have any idea what the maximum one could expect frozen butane to dissolve of thc in the kief.
    I would like to put more than enough kief in the thermos, but not excessively too much.
    Prior to my finding this site, I used to blow butane thru a tube filled with partially ground flowers. My maximum return was about 6 grams of honey oil from 1 can of (not frozen) butane ….. can I expect more from the thermos/kief/frozen butane?
    The kief that was partially extracted with 2 cans of butane, I dried, mildly reground with a coffee grinder, and covered with 99% isopropanol. The resulting liquid was quite green.
    I’ve put that in the sun for a while, and wrote this question while waiting for the green to fade. I have a feeling that the thc quantity from the iso wash will outweigh the results of the 1st 2 butane extractions, which is why I would like to have a better idea how much kief to use with a can of butane, in the first place.

    If I used a device like the mark III terpenator, how much kief would I be able to extract, in how long?
    Enjoy Labor Day
    Thanks as always

    • I usually extract kif at least three times with a thermos. It is hard to get it to dissolve without agitation and agitation will speed the butane on its way.

      A thermos will extract more resin than a column, but is more work.

      We run a 1 1/2″ X 6″ column on the Mk IIIA for extraction bubble and kif. I usually use four 10 second floods for full extraction. It leaves behind a light tan dry non sticky duff.

      • I guess learned several things with this trial. The ss Thermos will hold wildly too much kief to ever get extracted. I put about 2 ozs of prime kief in the thermos … it appeared to be half full – one can of butane was well above the kief. I think a can of butane will only absorb enough thc to result in the range of 6 grams of Absolute Amber (after winterizing with ethanol). I would rough it out at about 15 grams of kief, 20 grams to be really sure, that can be dissolved by the butane in the thermos. It really appears that to use kief with butane requires a closed system … why bother creating kief, if you can blow thru a tube full of flowers (that could have been turned into kief) and get the same return. The closed system changes the dynamics.

        The kief that was not dissolved by the 2 butane runs, I decided to dissolve in 99% isopropanol. I learned a few things in that as well. I let the iso and the kief remains sit overnight, and used a generous amount of iso to insure that I ‘got’ almost all the remaining thc.

        Talk about green … what a surprise to me how green the iso was after filtering, as the kief was light golden in color. I put this filtered iso-thc liquid in a jar in the sun for no more than 2 hours and it was no longer green, but, more like dark honey color. It seemed to me that the green broke down quicker in iso than it does in ethanol, as well.
        I evaporated this in a pyrex dish with a fan and a hotpad on low. I scooped off more than half (it still had some iso in it) and dissolved the rest in 192 proof ethanol, which I then placed in 0f freezer to see what might filter out. I was hoping at least the chlorophyll breakdown products might filter out.

        Another big surprise awaited me. After 24 hours in the freezer, I filtered the liquid thru a coffee filter in a funnel, into another jar, all in the freezer. I’ve had the feeling in previous winterizings (standard ones butane first then ethanol) that by the time the ethanol had all drained thru the coffee filter, it had warmed up enough to redissolve some of the waxes in the filter…. which is why I’ve switched to filtering in the freezer. Anyway there was a relatively enormous amount of tan color ‘stuff’. I recall you wrote in response to a question recently that iso was not as good to use for winterizing ….. this certainly bears that out … ethanol is much pickier.

        I put this ethanol filtered liquid in a pyrex dish over a hot pad on low, with a fan blowing gently on it. When the thc coated the bottom, I poured the whitish liquid off carefully, but thoroughly, as it can only contain impurities, as thc does not dissolve at all well in water. I scraped scooped the remaining product it was not quite hardened (still some ethanol to remove) into a cupcake paper made out of parchment (quite a convenience for the final purge). Into my vacuum chamber (which is (shudder) a ball jar with a vacuum hose thru the lid that I’ve used for more than a year without problem) which rest on a hotpad on high. The ball jar allows me to watch whats happening from all sides. As there is very little alcohol left I can carefully vacuum off the remaining alcohol in the parchment dish, working with letting in some air if the ‘muffin’ puffs up too much …. and not have to change the oil in my vacuum pump.

        The results have all the holes that my honeycomb use to have …. but are rock hard, not at all waxey or soft … and not sticky in the slightest. When held up to the light the thinner parts are very much amber, while the thicker parts are somewhat darker.

        The other part of iso product that I originally scooped off, I dissolved in ethanol and put in the freezer …. but this time I will leave it there a 2nd day as well, in the hopes of removing even more impurities.

        Is it possible to winterize somehow, by dissolving an iso or ethanol created raw thc resin in butane (not in a closed system), and then filtering and evaporating and purging the butane?

  57. Posted by Bhombsnotbombs on September 2, 2013 at 9:26 AM

    Just wondering if there is any way to de-wax your product and still produce a honeycomb consistency ? Or is it really the waxes and lipids pulled off during extraction that cause the butter or honeycomb consistency ?

  58. Posted by Peter McDonald on August 28, 2013 at 1:26 PM

    Perhaps i am ignorant but someone please comment as to galvanized steel. It is conspicuously absent from the analysis of column materials. What is the problem with zinc?

  59. Posted by gilmourofcurtis on August 27, 2013 at 5:26 PM

    Is there such a thing as solventless winterization? I think my friend wants to remove fats and lipids some full-melt cold-water. Sorry if i’m posting in the wrong thread.

  60. Posted by Taylor on August 26, 2013 at 5:48 PM

    Hey Skunk Farm

    just wanted to thank you guys for the outstanding amount of info you have provided, if used both you thermos and column techniques to make some fantastic oil.

    My question is one of opinion. We (myself and friend) were talking about refluxing in DCM (dichloromethane) and have a condenser above the evaporation flask
    so the solvent heats up but goes back down the condenser when it turns to gas. Just wondering your thoughts and recommendations on this technique

    Thanks a lot guys, again, by far the most reliable and legitimate info you could possibly find on extracting oils anywhere



    • I don’t like Methylene Chloride for extractions, because of its health hazards like cancer, and mutations, etc.

      Section 11: Toxicological Information
      CAS#: 75-09-2: PA8050000

      LD50/LC50: CAS# 75-09-2: Draize test, rabbit, eye: 162 mg Moderate; Draize test, rabbit, eye: 10 mg Mild; Draize test,
      rabbit, eye: 500 mg/24H Mild; Draize test, rabbit, skin: 810 mg/24H Severe; Draize test, rabbit, skin: 100 mg/24H Moderate;
      Inhalation, mouse: LC50 = 14400 ppm/7H; Inhalation, rat: LC50 = 52 gm/m3; Oral, mouse: LD50 = 873 mg/kg; Oral, rat: LD50
      = 1600 mg/kg;

      Carcinogenicity: CAS# 75-09-2:
      ACGIH: A3 – Confirmed animal carcinogen with unknown relevance to humans California: carcinogen, initial date 4/1/88
      NIOSH: potential occupational carcinogen
      NTP: Suspect carcinogen
      OSHA: Possible Select carcinogen
      IARC: Group 2B carcinogen

      Epidemiology: There are few reports of injury despite widespread use of dichloromethane (ACGIH, 1991). Solvent abuse has
      led to death (Harbison, 1998).

      Teratogenicity: Inhalation, rat: TCLo = 4500 ppm/24H (female 1-17 day(s) after conception) Effects on Newborn – behavioral.;
      Inhalation, rat: TCLo = 1250 ppm/7H (female 6-15 day(s) after conception) Specific Developmental Abnormalities -musculoskeletal system and urogenital system.

      Reproductive Effects: Reproductive effects have occurred in experimental animals.

      Neurotoxicity: No information available.

      Mutagenicity: DNA inhibition: Human, Fibroblast = 5000 ppm/1H (Continuous).; Morphological transformation: Rat, Embryo
      = 160 umol/L.; DNA damage: Oral, rat = 1275 mg/kg.; Inhalation, mouse: TCLo = 2000 ppm/5H/2Y-C (Tumorigenic -

      Carcinogenic by RTECS criteria–Lungs, Thorax, or Respiration – Tumors).
      Other Studies: See actual entry in RTECS for complete information.

      • Posted by Taylor on August 27, 2013 at 11:17 AM

        Would you say after a extensive purge in a vaccum chamber with heat, that you would still be concerned about the toxicity levels? I found the thermos technique allowed plenty of time for the bud to soak in butane for all essential oils and alcohols to dissolve, buy DCM would allow an extended soak time

        • All of the solvents can be removed below levels of immediate health concern, but I consider the longer term chronic effects, when things have been identified as a carcinogen, teratogen, mutagen, etc.

      • Posted by Taylor on August 28, 2013 at 12:08 PM

        As well would refluxing in other organic solvents like toluene or hexane be a viable option? OR perhaps a acetone reflux with a toluene wash of the crude oil?

        Sorry for all the questions! Trying see if refluxing will increase yield in anyway. Again thanks for all the help!

        • Hexane works well if adequately purged so as to not raise concerns for 2.5 dione metabolites.

          Tolulene concerns me from a mutagen, teratogen, and birth defect standpoint.

          Section 11: Toxicological Information

          Routes of Entry: Absorbed through skin. Dermal contact. Eye contact. Inhalation. Ingestion.
          Toxicity to Animals:

          toxicity (LD50): 636 mg/kg [Rat]. Acute dermal toxicity (LD50): 14100 mg/kg [Rabbit]. Acute toxicity of the vapor (LC50): 440
          24 hours [Mouse].

          Chronic Effects on Humans:

          CARCINOGENIC EFFECTS: A4 (Not classifiable for human or animal.) by ACGIH, 3 (Not classifiable for human.) by IARC.
          May cause damage to the following organs: blood, kidneys, the nervous system, liver, brain, central nervous system (CNS).

          Other Toxic Effects on Humans:
          Hazardous in case of skin contact (irritant), of ingestion, of inhalation. Slightly hazardous in case of skin contact (permeator).

          Special Remarks on Toxicity to Animals:
          Lowest Published Lethal Dose: LDL [Human] – Route: Oral; Dose: 50 mg/kg LCL [Rabbit] – Route: Inhalation; Dose: 55000

          Special Remarks on Chronic Effects on Humans:
          Detected in maternal milk in human. Passes through the placental barrier in human. Embryotoxic and/or foetotoxic in animal.
          May cause adverse reproductive effects and birth defects (teratogenic). May affect genetic material (mutagenic)

  61. What is the consistency of the absolute in the picture above? I’ve most recently been using a box fan w/an a/c filter on the intake to purge as much of the ethanol as possible after the 48 hour soak, by placing my open topped Pyrex in front of the fan on full speed. I don’t get any foreign items in the oil, as the filter is obviously effective in catching any visible contaminates & the air flow keeps anything on the other side of the fan from falling into the dish. This has saved me the headache of changing the vacuum oil out, at all, during the entire oven purge. Also, bubbles have been limited to very few in # @ 115 & my sea level adjusted vacuum level. I feel as if the purge would be complete in 30 mins. This time I came out with hard shatter in the amount of time I would have yielded goo, had I not used the fan purge. Which brings me to my point: I feel as though I’ve lost flavor & aroma w/the hard shatter vs. the goo. It may be that I had shatter long before I removed it from the oven, but I wanted to find out which you prefer if everything is done properly.
    Best Regards,

    • The absolute in the picture is shatter and flint hard. I had to warm it to scrape it up.

      Some monoterpenes are lost with winterizing, as they leave with the alcohol whether you use heat or vacuum. It is a trade, as some of them smell and maybe even taste good, but add harshness to the oil when vaporized.

      Using a fan works well when the humidity is low, but alcohol is hygroscopic and on a high humidity day, you may end up with a lot of water in the alcohol, and a light tan watery solution toward the end.

      • Ah, I see. That would not be good. Luckily, I’m in Colorado. Not much humidity to speak of, but I will keep an eye on it. What humidity level would be a show stopper? I imagine on most days, I’d be fine outdoors. But, if there’s a more preferable method, lmk! I also make kava and kratom tinctures, & I use a still to remove the ethanol from those… I’m considering selling it and just getting a cold trap. Do you guys endorse, or have you begun selling, a cold trap such as the one you designed? $500 sounds a lot better than $3500. One more question: Approximately, what amount of time would you say it takes in the oven @ 115 w/vac, considering the ethanol is nearly dissolved at the start? Thank you so much for the info! There are many people enjoying much higher quality, and healthier, medicine because of the time you guys have so generously put into spreading the truth.
        Best Regards,
        Robert G

        • Probably below 50%.

          Still playing with our cold trap design but will publish more build information after I have run it longer and tweaked the operating parameters.

          Cold boiling is slooow. It takes all day to pump off a quart.

      • How warm do you get it to facilitate scraping?

  62. Posted by Funkydslr on August 24, 2013 at 5:40 PM

    How would you recommend one purge 100+ grams of oil at a time. It’s usually split between 2, 5 gallon vac chambers down to 30hg for 6 hours at a time, but it’s still not shatter at the end. Even exposing it to as much surface area as possible at 110 degrees isnt quite producing patient quality results. Lost at this point.

    Thanks for the help!

    • I would split up the sample into more lots, so that I could run them in a thin film at 115F and -29.5″ Hg. It takes less than an hour, so you could run it six times in 6 hours.

      6 hours at even 110F is long enough to partially decarboxylate, which will leave it soft.

  63. Posted by tony on August 23, 2013 at 11:38 PM

    I got a question I did a run my bho came out sappy orange an its unstable even if I put it in the vac for hrs what should I do? It looks bright red orange see thru. Thanks

  64. […] rn rn-Skunk Pharm Researchrnrnrnrn Quote:rn rn […]

  65. Posted by ched on August 21, 2013 at 1:43 PM

    Hi Skunk Pharm. Thanks for the write up and consistent commenting. I have typically been doing small runs (roughly 11g of plant material in my extract tube) and my typical methodology is as such:

    -pre-freeze nugs for about 20 minutes or so
    -pack tube with nugs broken up as little as possible to preserve cell membranes, trying to get an even pack
    -blast directly onto an oil slick mat which is lining a pyrex dish, then float this dish in a large pot of water on the stove

    i use an IR thermometer making sure to keep the surface temp of the oil pad < 115F, letting this go for a few hours until bubbling has stopped. At this point, I usually use the oil slick pad to roll the oil onto itsself. This results in pretty much 0% loss by way of dust from scraping and such, but the last couple times i've done it, after a few days my oil has gone from a nice log to…literally sappy sometimes liquidy oil. Clearly I am doing something wrong (especially since my reason for blasting is to load into my portable vape which works best with shatters.

    So I guess my questions are:
    A) For this size and purpose would you recommend the standard extractor tube method or the thermos method


    B) When you're ready to finally empty your oil once the evaporation has taken place, how are you doing this? Am i understanding correctly that you're re-dissolving your BHO in ethanol and then re-evaporating this? Are you still able to get shatters this way and do you feel like you're having any additional product loss by this additional dissolving?

    • For 11 grams I would use a thermos.

      I redissolve in ethanol and freeze the alcohol mixture for 48 hours to precipitate out the waxes, and then filter the solution to remove them.

      If I reliably want shatter, I then cold boil the alcohol away at 115F and -29.5″ Hg vacuum.

  66. hey guys hope all is well. so people are finding that there is a “mystery oil” in canned butane(possibly a lubricant for the lighters its meant for?) my question is if activated carbon would remove it

    • My guess is the mystery oil is Pentane, the closest heavier fraction to butane, that would be a liquid at ambient. The other two fractions present in butane are propane and isobutane, but they wouldn’t be a liquid at ambient temperatures.

      Pentane does a pristine extraction, is easily purged, and of low toxicity.

      All of the simple alkanes are single bonded carbon atoms, with the remaining bonds filled with hydrogen, including the longer chain alkanes used for lubricating oil. Why anyone would have to add a lubricating oil for the “valve” is the pregnant question, because it not only isn’t required using butane, it would not feed well through the small orifices of a butane lighter and would produce poor flame characteristics.

      • Posted by Dave on August 22, 2013 at 11:43 AM

        How would one go about removing the Pentane?

        A few people are saying that this mystery oil might make open blasting a thing of the past…


        • We like to purge at 115F and -29.5″ Hg.

          As a tongue in cheek thought, it is certainly one more good reason to use a closed system, but that conjecture before the mystery oil is identified would be premature. It is certainly of concern until it is, but it could easily be things that we already know are in butane, such as oleaginous waxes and sulfur compounds at low levels, which are being concentrated.

  67. Posted by Alaskan Dromie on August 19, 2013 at 2:40 PM

    First off, thanks for all the amazing detailed info! A buddy from jointogether referred me to your site and I must say, I love how in depth and explanatory you make everything :) that said, is there any way to remove the waxes while preserving the terpenes? I’d like to remove the waxes, but as the terpenes are also extremely beneficial medicinally and also add flavor I’d like to keep them. Sorry if you covered that at some point, any help would be greatly appreciated! Thanks again

  68. Posted by Brad on August 16, 2013 at 8:34 PM

    I’ll first make an assumption (yeah I know) that no-one else has posted this in the reply’s below – I just don’t have time to read them all.

    Secondly I’ll say how excellent I consider MOST of the info on this site, even though I’m about to criticize just a few facts.

    The article above states:

    “Butane Honey Oil, or BHO, is the essential oil from the cannabis plant, extracted using n-Butane as a solvent. If it is extracted from fresh material, it is a Concrete, and if from cured material, it is an Oleoresin. A concrete or an oleoresin that has been winterized to remove the waxes, lipids, and fats, is known as an Absolute.”

    In fact the essential oil of cannabis was clearly defined about a century ago (before THC’s structure was known) and IT HAS NOT CHANGED from being the volatile fraction obtained via steam distillation (only ~0,5-2% by wt. of cannabis). Cannabis essential oil (which is available from at least 2 essential oil sellers I know of: one Canadian produced and one Swiss produced) is totally legal worldwide, since it is devoid of any cannabinoids and is composed almost entirely of terpenes and terpenoids (there is a slight diff.).
    BHO is in fact basically a mixture of the cannabis essential oil + cannabis cannabinoids (absolute) + cannabis waxes and lipids (which includes fats) + traces of a few other impurities.
    I would suggest that BHO is in fact a ‘concrete’ whether extracted from fresh material or cured material, since the only difference would be a slightly lower level of volatile components (mainly the essential oil) and most ‘concrete’s produced by the essential oil industry (mainly for perfumery & food flavorings) are made from dried (and/or cured) plant material which is almost identical in composition to that of fresh plant material.
    An ‘oleoresin’ is normally extracted from plant material using Ethanol, which dissolves both lipophilic (fat soluble) as well as hydrophilic (water soluble) compounds and thus produces a product with a whole bunch of additional impurities not found in a lipophilic extract eg. from hexane (the standard solvent in industry) or liquid butane extraction. Thus a concrete will produce an ‘absolute’ upon winterization (wax & lipid precipitation), however an alcohol extracted ‘oleoresin’ will not form a true ‘absolute’ upon winterization, since additional impurities are present.

    Otherwise, guys keep up the damn good work at SPR!!!

    Just say know…

    • Thanks for the insight bro and sorry to take so long to answer this one, but I kept setting it aside to go read Geunther some more before answering.

      Tis true that Essential Oils were first extracted using steam and thus only included the mono and sesquiterpenes, while the cannabinoids are diterpenes with too high a boiling point for saturated steam.

      It is also technically correct that nothing extracted using a solvent therefore qualifies and that is technically absolutely correct, but given that we are extracting the exact same mono and sesquiterpenes and the diterpenes using a solvent, for some of the audience that is cutting the details a mite thin.

      In the spirit of cannabis “Active” oils extraction, Absolute Amber is a term covering a mixture of essential oils, ranging from Isoprenes, to poly-terpenes, that was extracted using a non polar solvent and winterized using a polar solvent.

      If you are selling cannabis essential oils in most places in the US, you are in violation of both local and federal laws if they contain the diterpenes like the cannabinoids, so that thin slice of fact would be damn important, so it is an excellent point.

      I will review my verbiage and amend it to reflect the difference.

      The biggest problem with mono-terpenes is not extracting them with a solvent, it is holding on to them while evaporating away the solvent. Many are alcohols, ethers, aldehydes, ketones, etc, with a high vapor pressure themselves, so are happy to leave with the alcohol being distilled off.

      In fact, if you sniff and taste the alcohol distilled off using a simple pot still, it will be a gin like spirit, tasting of floral mono-terpenes.

      Same with vacuuming off the solvent without heat, the vacuum pump oil begins to smell more floral than the end product.

      With steam, they just condense the steam and float off the oil as it falls out of suspension. They also market the condensed steam as a hydrosol.

      We’ve considered steam extraction for the mono and sesqui-terpenes, followed by solvent stripping the remaining terpenes, and recombining them, but need to mock up an experiment before jumping in with both feet, because the steam may have some effect on the quality of the heavier terpenes.

      I thought we had a joint experiment set up with a steam extractor, but it didn’t work out, so we’re holding that experiment off until I complete the fractionating still and we can run a column of material on it, vis a vis the fractionating column packed with stainless ribbon.

      Probably not as efficient as the big boys, but it should still tell us enough to know whether we wish to proceed with something more elaborate and spendy.

  69. Posted by Gary on August 16, 2013 at 12:36 PM

    If I extracted in to a teflon evaporating dish (like the one I posted in the link below) that’s in a pyrex dish with some vegetable oil in it; on a hot a plate to do the heat purge. Then I put the teflon dish in the freezer. Would it just come out without scraping? Is this a good idea to use PTFE?

    Thanks for any help and this awesome resource.

    • There are folks using and swearing by PTFE and as long as you don’t burn it, it should be good. When burned, it releases HF acid. Unless you are scraping with a blade, I don’t see PTFE getting into an extract.

  70. Posted by Gary on August 15, 2013 at 3:30 PM

    If I extracted in to a teflon evaporating dish (like the one I posted in the link below). That is in a pyrex dish with some vegetable oil in it; on a hot a plate; to do the heat purge. Then I put the teflon dish in the freezer. Would it just come out without scraping? Is this a good plan for my first run?

    Thanks for any help and this awesome site.

  71. Posted by mikey on August 14, 2013 at 3:11 PM

    thanks for all of the helpful information. i have been spraying onto a silicone mat untill i have read your article on the “sponge” like characteristics of said mats. with that being said, the talk about spraying into pyrex pans has me thinking about the gathering process and having product lost on the sides of the pan. are there any helpful hints or tools to be used and achieve a clean run with a high yield and minimizing the contaminates in my errl.

    • Either freezing the extract to make it super brittle and easy to chip with a razor, or washing it out with ethanol and winterizing it work for us.

      I also sometimes wash oil out with the minimum amount of alcohol, and then evaporate that off using vacuum, if the yield is small and I’m trying to preserve every last shred.

    • Posted by Sterling on December 18, 2013 at 3:22 PM

      make a boat out of parchment to set in your pyrex. once your butane boils off and your oil hardens a bit it will stick to itself and not the parchment so much. easy to handle and no loss or mess. also easier i find to do low temp purges by setting it on top of a glass bowl in heated water by a hot plate/crock pot of some sort.

      • Posted by Sterling on December 18, 2013 at 3:27 PM

        I wanted to clarify the importance of the parchment not overly touching the glass so as to be heated by the air and thus maintaining a lower temp than the heating device can reach on it’s own with previous methods. i have only done this with small quantities 1-6gm.

  72. Posted by Chris on August 12, 2013 at 9:08 PM

    If a column is loaded with frozen material and the extractor is reassembled and then drawn into a vacuum, doesn’t the frozen material thaw out? I recently put some dry trim in an open container and put it into the refrigerator rather than using the oven. It seems to have dehydrated the trim nicely. Is this an acceptable technique or is the trim being damaged in some way?
    I have been getting excellent test results on my oil and owe it to Skunk Pharms!
    Thank you

    • Thanks for the good thoughts Chris!

      Yes, frozen material thaws out in a column, but the injected butane is close to freezing temperatures, so it still stays cold. It refreezes again during final vacuum recovery.

      Freezing to tie up the water is an acceptable technique, and one which we use with fresh cut material.

  73. Posted by Hands on August 6, 2013 at 2:10 PM

    Iv’e not tried the BHO method, but I just had a thought for the thermos extraction. Would setting a stainless steel thermos inside a custom dry ice cooler surrounded by the dry ice for an extended period of time allow for the material to be winterized in the butane before filtering it the first time? I wonder if the maintaining temperatures of the Butane and Dry Ice would correspond to cause winterization, but I guess that would depend on the key factors that result in the catalyst of “winterizing”. . . thoughts? You guys are my heros … Cheers

    • Winterizing is extracting with a non polar solvent like butane and then redissolving the extract in a polar solvent like alcohol, before freezing for 48 hours or so, and filtering out the precipitated waxes.

      It works because the polar solvent really doesn’t like the non polar waxes much and dumps them first as its ability to hold the solute in solution falls as its temperature drops. That wouldn’t happen the same using a non polar solvent for both.

      • Posted by Hands on August 9, 2013 at 1:44 PM

        I see… thanks for the clarification. After reading your QWET method, I see that you are starting with ethanol and then winterizing with the same solvent? Basically why is it that the polar to polar in that case is working or am I missing something? I apologize if this is a stupid question as I am still refreshing all the distant memories of my chemistry lessons. Thank you for you patience, Bless

  74. Posted by chris on August 5, 2013 at 12:18 AM

    So the removal of carboxylic acids will make oil sappy in texture? True or false?? And what is cold boiling?

  75. Posted by chris on August 3, 2013 at 2:31 PM

    Also as im doing bigger runs than my usual im not getting shatter from C4H10 extraction. Purged at sun temp in in the PNW. Why is this? is it too thick? Whats your suggested thickness? And its confusing because when i was doing smaller runs i got great shatter every time. novac used

  76. Posted by chris on August 2, 2013 at 2:15 PM

    How would you go about processing a QP of bud that is old and dry? Hand break it up then use butane?, NaCL wash? Wintetize? Should i freeze the plant matter?Going to chose quality and color over quantity. Thank you

  77. Posted by Zipdeez on August 2, 2013 at 11:16 AM

    Do you usually always winterize your bho? I have been blasting bho for a long time – never have tried winterizing it with ISO. Have recently been enlightened into using it to make shatter. Is washing your bho with alc usually a good outcome? I simply blast, heat purge, then throw it in the vac oven. It almost always honey combs after awhile.

    Thanks for the amazing site.

    • Winterizing removes the plant waxes and I do usually winterize my extracts because I don’t want the waxes coating my lungs when I vaporize, diluting my oral meds, or lingering behind on the skin when used topically.

      Moderation in all things, including moderation. Sometimes I don’t winterize to achieve a particular effect, usually as requested by others, but sometimes just for more flavor.

  78. Posted by scott zcollett on August 1, 2013 at 9:15 PM

    I was just wondering if you have been around or have any knowledge of expression extractions of cannabis.

    • Not by that name. What is expression extraction of cannabis?

      • Posted by scott zcollett on August 2, 2013 at 8:38 PM

        it is cold pressed at extremely high pressure that gets slowly increased. Dont know too much about it myself and was looking for insight. You can google the process as there are 3 different types.

  79. Posted by 215dank on August 1, 2013 at 1:22 AM

    I have two questions for you. the first is have you ever seen what I would assume to be floating waxes and frozen water in your oil after sparying but before all the liquid tane has evaped? My theory is since the butane is below freezing at this time they become solid, they look almost like little icebergs and I seem to get more of these when i chill my butane before blasting. I have seperated these a few times and they always become cloudy and gross looking oil with sugary water like pockets. just wondering if you could give me more knowledge on what this is or if you have experienced this.

    My next question is have you ever heard of using uv to break down cellulose in bho? I was recently told since cellulose is hygroscopic the uv will help break it down in return breaking down the waxes and water held by that cellulose. Doing this should benefit the clarity and make it alot harder to achieve a butter/wax like state. Yet again would just like to hear your thoughts on this.

    • Yes, when we spray in a shallow dish, the humidity from the air forms ice around the edge of the evaporating pool of butane and contaminates our oil with water. That is why we started spraying into a bain marie pot, sitting in hot water, so that the evaporating butane keeps the moisture laden air out of the pot and away from the evaporating pool.
      Cellulose is not readily broken down by UV light, so I’m unsure of how such a thing might work. Do you have more detail?

      • Posted by 215dank on August 1, 2013 at 12:32 PM

        To my knowledge it could be broken down by uv but this is something new that I have only experimented with a few times giving intersting results. I’m no expert on the subject yet but it may be something to look at

        • Breaking down cellulose with UV is a long term project, not something typically done in an essential oil, because the same UV is at least an order of magnitude more damaging to the aromatic alkene hydrocarbons.

          Plants use cellulose in their structure, specifically because it is strong and UV resistant.

          One of the above studies uses titanium dioxide to catalyze a faster degradation and the other is a long term study.

          My first question would be why there is cellulose in the BHO in the first place?

          If I found some and wanted it out, I would personally use a 0.2 micron syringe filter, not try to break it down into byproducts that would remain behind in the oil.

          • Posted by 215dank on August 2, 2013 at 2:24 PM


            I guess those weren’t the best examples to link but you get the point that it is able to be broken down by uv, just another reason why growers give their plants 48 hours darkness before chopping due to degradation of trichs. there aren’t many scientific studies I could find on uvs reaction with trichome cellulose. Cellulose is not desired in the extract but usually comes through with the trichromes during extraction since they are incased in a wall of it. Cellulose generally makes its way into your extract hence winterization to process it but if you winterize your extract you will remove valuable terpines that could be saved with low heat and uv IF this tech really works. I appreciate your insight and knowledge, thanks for helping me to get to the bottom of this and see if theirs any truth behind it.

          • The cellulose comes along with the trichomes when dry sieving or making bubble hash, but isn’t extracted by Butane. There should be no cellulose that needs to be broken down.

  80. Posted by chris on July 31, 2013 at 4:31 PM

    Should i run fresh frozen then dried for a 2 days or cure my plant matter before i blast or should i use liquid nitrogen to lock up all the chlorophyll and blast away. Im aware that ice formed on leaves will not release the heads. This is for vaporization and plan on making it absolute later, i really would like to have pretty bho to start bfor i winterize it. Also i was told that 80-110° is shatter 110-120° is wax and 140-160 is sappy? Whats your take?

    • We make shatter from ambient to about 115F. Wax can be made at a wide range of temperature and time at vacuum, but 140/160F will partially decarboxylate and be sappy.

      • Posted by chris on August 1, 2013 at 2:44 PM

        Thank you, but im still lost a lil bit lost heres the scenario, 1lb fresh cut frozen (A-grade)trim strain black berry kush, i let it air dry for, 2 days till it was dry but still soft like . Put plant matter in 2″ x 2′ vessel. Extracted in a small Pyrex pan an used the sun to purge it was about 1-2 inchs in thickness and got very dark oil sappy, amber when light is behind it. My variables are ( plant matter dryness) (heat useds during extraction) ( oil thickness over all) ive seen the same strain in wax look light in color mine is dark what should i change to achieve a lighter oil in color and get shatter every time? Thank you for your help

        • Sun purging can get the alcohol solution hot enough to caramelize plant sugars. Cold boiling under vacuum would eliminate that variable.

          The color of the trichomes when harvested can also have an effect on the color or the oil. Amber trichomes make a darker oil than clear or cloudy trichomes.

  81. Howdy! I could have sworn I’ve been to this blog before but after browsing through a few of the posts I realized it’s new to me.
    Nonetheless, I’m certainly happy I stumbled upon it and I’ll be bookmarking it and checking back regularly!

  82. Posted by Bikini on July 28, 2013 at 7:13 AM

    My Brother was given 14 months to live when the Doctor finds out that his body cannot take Chemo anymore. ever since then, the family have been in pain knowing that they where going to loose a precious son that was just 23 years old to Cancer of the lungs. my mother did a lot of research when she found out that cannabis oil was the cure all medication for cancerous diseases, that was highly guaranteed to cure all cancers and other various diseases. my mother bought the Hemp oil for my brother and he has just completed his treatment 3 weeks back. his latest test result indicated that his cancer has been gone without a single trace in his system. Thanks to Rick Simpson and Thomas Kelvin where the Hemp oil was purchase. (edit address)

    This really is a miracle to the new generation. Bikini

  83. Posted by MB on July 27, 2013 at 1:29 PM

    Hey guys I had a question about silicone baking dishes….

    My process involves me spraying directly into a container with 192 Proof Alcohol…. My question is that once the butane has evaporated and I am just left with the alcohol solution, is it safe to tranfer this into a silicon baking dish for final evaporation of the alcohol?

    This has made my life extremely easy but I am just curious if there is anything in the alcohol that could react with the dish to bring in unwanted contaminents.

    This is used for vaporizing
    Thank you for your help…..

    • The Cole Palmer chemical compatability chart shows that silicone rubber is only “Good” with ethyl alcohol. Here is the link and an explanation of what good means:

      Ratings — Chemical Effect
      A = Excellent.
      B = Good — Minor Effect,
      slight corrosion or
      C = Fair — Moderate Effect,
      not recommended for
      continuous use. Softening,
      loss of strength,
      swelling may occur.
      D = Severe Effect, not recommended for ANY use.
      N/A = Information not

  84. Posted by C4h10 on July 26, 2013 at 8:53 PM

    Hello again! I was thinking of switching from un bleached coffee filters to paper lab filters for the bottom of my column. I was wondering what micron size would be best? And what kind of flow rate should I look for? I normally don’t winterized and its for vaporizing if that matters. Thanks for all the help!

    • The coffee filters are about 20/25 micron nominal filters, so a lab filter in that range would duplicate the results.

      With a deadhead filter, flow rate is moot as it changes every time a particle plugs a pore. If you stayed in the 10/25 micron range, I predict that it would work.

  85. Posted by Dro Hernandez on July 26, 2013 at 10:24 AM

    Hello and thanx Pharm! There’s lots of insightful information given here, and greatly appreciated. Ive ran about four extractions in my recent time, each time trying a slightly different method. Ive attempted using a 12″ glass tube, a small honeybee extractor, and a large honeybee extractor, each time using dry cured sugar trim mixed with small bottom of the barrel buds. Ive ran every tube twice, meaning i used two cans per tube, and every time I’ve yielded the same 4-5.5 grams.
    Ive tried the hot water bath purge, as well as whipping the wax while under-heating the pyrex. I really like the consistency of the wax i got back after whipping and under heating most, but im really interested in trying a vacuum purge.. Can you point me to link where i may be able to purchase a reliable inexpensive vaccum, or if possible, a simple dys link.
    My biggest issue i have is trying to produce a larger quantity, i havent been able to get over 6 grams, using 2 cans with the same filled tube. Im really looking to produce at least 1oz. Any help??
    Thanks again S.PHARM

  86. Posted by greenbean on July 24, 2013 at 8:58 AM

    Thermos or column? Which is better

    • Depends on what you are making. What material and what end product do you covet.

      • Posted by greenbean on July 28, 2013 at 5:35 AM

        A quality oil to vaporize. Currently I’m running a simple turkey baster setup with average of 17% or so after a single flow through. I want to be as effective in recovering as much resin as possible aswell of course. After emptying the turkey baster each run I have saved the material for a second wash I was going to do with just ethanol rather than butane again, because of such drop in quality of a second butane wash, and just use it for edible meds. Edibles tend to not do much for me so I was wondering if the thermos would recover more resin effectively the first wash rather than the way I am doing it now?

        • At 17%, you are pretty close and a thermos soak would pick up more the first time. What are you pickling up after repacking and making a second run?

          • Posted by greenbean on July 29, 2013 at 3:41 AM

            I have yet to try that. I have been doing extractions for almost a year and just got serious about two or three months ago. I have ran the column without repacking out of curiosity one time and got a 1% return and the quality was not near the same. This is why I was thinking about just doing ethanol for the second wash and just use for edibles. That being said, would it be worth the extra work to go about the thermos method to retain more yield the first wash

          • The difference is in the neighborhood of 3%, of a lower grad medication. The bigger question might be how much that amount of time and effort are worth to you?

  87. Posted by sshguy on July 24, 2013 at 5:07 AM

    I read that everclear should not be used as to it having sugar and some sort of flavoring in it. Could you clear that up for me?

    • A myth. The other 4.5% of Everclear is water. There is no flavoring added or present in 190 proof ethanol.

      • Posted by sshguy on July 24, 2013 at 7:45 AM

        thank u for such a fast response. If vaporizing, do you always winterize? Return percentage is so minimal already I was hoping to find it to not be needed, but after numerous days reading through your site it seems to be highly recommended

  88. Posted by HealingGreen on July 24, 2013 at 4:57 AM

    First off id like to say thank you very much for your help to us all. I am looking to end up with a flavorful end product that is smooth and does not irritate the throat when vaporized. I currently vac purge the butane and it does a great job at doing that but my throat still becomes irritated after vaporizing. Is winterizing going to be my best option or should I only vacuum purge the butane if I want to keep any flavor terpenes?
    One other question I have is should I scrape up the bho from the pyrex and onto a pad/parchment or would I benefit at all from putting the pyrex directly into the vacuum chamber.
    Thank you so much for your help.

    • Winterizing will reduce the harshness by removing the plant waxes that induce coughing to expectorate them, and the monoterpene levels, which can also add harshness, because some of them, like Pinene for instance, are expectorants.

      You can purge either way, but we like a Pyrex dish and a thin film purge under vacuum.

      • Posted by HealingGreen on July 28, 2013 at 5:45 AM

        Thank you for your help. Can u suggest anything for scraping the pyrex with? I have tried razor blades and putty tools but it seems to me they have coating on them and it scares me to use them. I usually torch them to sanatize and get anything there could be off but after they cool I notice a thin film of flaking. Should I not torch them and just thoroughly wash with alcohol?

        • Acetone should remove the protective coating on the scrapers if you soak them in it. It is a thin plastic coating to prevent oxidation.

          You could also torch them and use steel wool, but that will wreck the temper in the scraper blades and they may no longer be springy.

  89. Posted by Pwankton on July 21, 2013 at 8:04 AM

    Three questions:
    1)In my quest for most efficient yield I found a recommendation for using stainless steel extractor tubes of 1/2″ ID max in order to avoid butane channeling. Reports of a significant increase over larger ID glass tubes in extracted yield, with no quality loss, are given and to me it makes a lot of sense, just seems like a pain to load. Your thoughts?
    2)Using previously dried and cured material, I have been using a food dehydrator for three or four hours at 95-100F before loading my typical glass flared boro tubes. Using many different starting materials, regardless of age, all of my extracts have ended up an amber colored shatter consistency. Aside from ease of handling, is there any real advantage to making other end results, like wax or crumble? The amber shatter that I end up with after a low heat vacuum purge is very nice but it is all that I end up with, am I missing out on something?
    3) Is “budder” merely a whipped extract or is something else done to it, like isomerization, to make it more psychoactive?
    Thank you very much for sharing your knowledge!

    • We found about 1″ to be the upper ID limit for an open extraction column and anything under about 3/4″ a royal pain to load and unload.

      I personally prefer shatter, but have made wax for folks who wanted it in that form. We make shatter first, and then turn it into wax.

      The extra processing removes a significant amount of the monoterpenes, which end up in the vacuum pump oil.

      The reason that waxes smell so aromatic, even with fewer terpenes, is that they started out concentrated in the first place, and so much more surface area is exposed with the wax hydrates.

      The down side to waxes, is that their aromatics and pungency are short lived due to the extra surface area exposed to oxidation, so you need to use them fast.

      Budder is just a whipped extract that has turned into a hydrate. It is no more potent than the oil it was made from.

  90. Posted by skepler on July 21, 2013 at 7:47 AM

    There are many comments regarding chlorophyll. I have long regarded this component to be an irritant when smoked. Over the years of growing, last year I had a few varieties of which I had two plants, and it was about to freeze at night. I harvested one green, removed shade leaves, hung for a few days, and cut into 18″ colas to age in containers. Trichromes just getting yellow. The second of each variety, I let go through the frost, and harvested within the week. This lets the chlorophyll break down into carotenes, reds and yellows of fall leaves, and sweetens the smoke. I can’t tell a difference in potency. I like to let my girls have a long life in natural light of at least six months, they start budding about now, at 15 weeks. I think the commercially grown products miss out on this aspect. I would be curious what yields commercial growers get/plant in their controlled short-cycling of the plant’s life. I find yield doubles with an extra 4-6 weeks.

  91. Posted by scott zcollett on July 18, 2013 at 2:48 PM

    I just wanted to check with you to get an address for the bho class next weekend. Im not very familiar with Portland and would like to know if there is ahotel in walking distance or close where I can stay.


  92. Posted by joey ellington on July 12, 2013 at 6:13 PM

    I just got into extraction ….So I just got a sweet ass glass Extractor for $25!, the ends flange out so the filter will not fly off.. they sold kits for more money, but it was just a mesh and a clamp… coffee filter and a rubber band works just great.. Save the $ Dont get the expensive one, just get the cheap one.(It does the same) Its small so you can run 20-25 grams at once. Perfect for the smoker, not the I dont work there an am not spamming… Just saying…….
    Anyways… I ran the butane 2x like everyone said and didnt get that much return.. Can I run it 3 times? What am I doing wrong? There is pressure in the tube. Im rinning a big can per oz.. Great herbs… ect..

    Thanks for your help…

    • $25 is a good price if it is a quality borosilicate column!

      Not sure about the low return. That column shouldn’t require more than one can of butane. What was the material and how was it prepared?

  93. Posted by MWiz on July 10, 2013 at 2:10 PM

    My goal is to make nice flaky wax, instead of the sticky, sludgy product. I do not have a vac oven, so I am purging the butane using boiling water, stirring, and time. The material I use has ranged from fresh cut buds and leaves, to stuff that has been cured and dried.

    My problem is being consistent.

    How can I consistently produce wax? And, would purchasing/making a vac oven aide me in this quest?

  94. Posted by chris on July 7, 2013 at 6:53 PM

    Questions about running fresh trim/ popcorn nug. If its fresh cut you say its the most pristine and its a concentrate. cured/ dry trim is Oleoresin.. I’ve made blonde bho crumble once but have failed the last 2 times i tried to repeat. Ive gotn fresh off the plant trim/ popcorn that’s been frozen, i dry it kinda for 2 days to release the ice that’s formed and then i run it. I’m getting chlorophyll justa lil bit but enough to make it darker than my usual. You talk about frozen fresh trim is best but frozen w/ no humidity to avoid ice on surface. All i want is blonde oil should i freeze fresh w/ no humidity or dry it more out what will make blonde amber. Oil

    • Oil color is strain specific, but on average a Sativa produces a lighter oil than an Indica and the oil is lightest colored, when the trichomes are still clear.

      Heat caramelizes the plant sugars and darkens them, so the extraction and purging has to be done with minimal heat.

      A vacuum purge at around 115F at -29.5″ Hg is the best way that we have found to purge oil with minimal darkening.

  95. Posted by eric on July 6, 2013 at 11:54 AM

    hey so i did a propane run today and i liked the way it worked, but for some reason it has a kinda odd way of drying out, any input on that ?, and also as well with a recovery system when using mixed gas do find its better to do the soak or let it pass through a few times

    • We get the best results with a soak.

      When you talk about the odd way of drying out, are you talking about the cotton candy like extraction?

      • Posted by Eric on July 28, 2013 at 9:39 PM

        Ya cotton candy like, but for some reason half the runs I do I can’t get them to dry out all the way. The bottom layer seems to stay sticky

        • The lower layer may be too thick.

          • Posted by eric on July 30, 2013 at 9:34 AM

            no it is super thin, and usually i dont have a problem, at first i though it was humidity, and it could b,, but i have been able to do runs in humidty just as high im at about 35%, the other issue is, could it be possible that my revocery tank has contaminent in it…?

          • If you put a thin film of the sticky material in a -29.5″ Hg vacuum at 115F, my guess is that you will find some retained butane.

  96. Posted by steve on July 5, 2013 at 1:43 PM

    I am looking to produce a high quality wax made purely for smoking or vaping. If I were to use the column method of extraction, would you recommend decarboxylation? Also, what method of purging would you suggest?

    PS. Thank you for providing all of us with quality information, knowledge can be very hard to come by in my area.

  97. Posted by eric on July 4, 2013 at 9:11 AM

    hey so have you seen the machine from ETS, i have one and i was wondering if you had any input on it, or if uve used it

    • No, but if you can guide me to a link, I’ll check it out!


      • Posted by eric on July 5, 2013 at 11:37 AM

        ya here it is, you may know who it is his name is matt,

        • Once the kif is separated from the green plant material, you can soak it in isopropyl as long as you like and you don’t have to do it frozen. Just mix them together and shake periodically until dissolved.

          Don’t worry about the wash time with kif, only with frozen green plant material when doing QWET or QWISO.

          Technically, winterizing is extracting with a non polar solvent and redissolving in a polar solvent, before freezing to coagulate and precipitate the non polar plant waxes, so that they can be removed by filtration.

          Since Iso and ethanol are both polar, the best you can do is extract with less polar isopropyl and winterize with the more polar ethanol. Neither should pick up that many non polar waxes anyway.

          I suspect you mean that the trichomes, rather than the terpenes settled to the bottom. After a solvent extraction, the trichomes have their essential oil removed and it is mostly stems and discs left. The resin will be in solution, not in suspension, so won’t settle or filter out.

  98. i want to buy one of these machines …. can you contact me? please!

  99. Posted by steve hill on July 1, 2013 at 6:19 PM

    Hey when you say you are freezing “fresh material”, are you referring to freshly cut off plant or just dried or dried and cured? And do you pack the glass tube and then freeze.?

    • I cut fresh cut colas to about 1/4″ size and pack into a column or thermos, before freezing. It is important to keep atmospheric air humidity from it during freezing, so as to not coat the trichomes with ice.

      • Posted by step on October 18, 2013 at 2:14 PM

        With regards to atmospheric humidity, would vacuum sealing freshly harvested material just before popping it into the freezer work?

        I am concerned about the non-existent air exchange causing a humidity spike before it gets down to freezer temp.

      • Posted by step on October 18, 2013 at 2:30 PM

        Additionally, you all mention freezing the column prior to extraction.

        For terpenator purposes, is loading 1/4″ sized fresh frozen buds directly into the column the right way to go about it? For throughput reasons I figure you all are not freezing the column every time..

        Where does drying until frangible fit into the equation? Does 200F lead to some partial decarboxylation?

        I suppose my goal is to make a fragrant, light-colored shatter while minimizing water pickup by the butane using the MkIIIA design.

        I will of course have a filter drier in line coming into the recovery pump, but I have noticed others have had issues with water saturating butane on this blog.

        Just trying to get the procedure straight in my head before starting out.

        Thanks again for your knowledge and support!

        • The oven dry is for material to be decarboxylated.

          For fragrant, light colored, bragging rights shatter, the best way that we’ve found is to just break the buds up lightly or pack them whole and instead of freezing them, extract using subzero cooled butane.

          We set the 50# refrigerant recovery tank in denatured alcohol and dry ice, and get the tank temperature down to below 0F. It doesn’t extract as many non polar plant waxes, or colored polar elements. Butane at that temperature also doesn’t pick up any water, or water solubles, where at ambient, it can absorb as much as 32 ml/L.

  100. Posted by Rosco cash on June 30, 2013 at 3:44 PM

    Hey so totally in related but u seem to really know ur shit n reply fast so I was gonna ask your opinion. This is the first year I’m doin it all myself out door. In Cali 5k elevation. Shooting for feeding nuits twice a week. I used two diff types of soil cuz got some free it’s that infinity heavy blend from humbolt. It says its good for 6weeks, with supplying nutrients. But other I used black gold. N some I mixed the two. I didnt lable all of them an wondering if its ok to still feed all them the nutrients I usually would or if that soil that’s packed with nuits could be harmfull if extra is added. Planted within the last month. Thx!

    • Hi Rosco,

      Good question! The safe move is to start light, no matter what you choose to do. I feed light even in newly transplanted soil, but that is out of habit (i feed daily) and unnecessary in a well blended soil.

      Most nutrient manufacturers recommend more then what is needed. It is easy to see their motive. Our usage should be directed by the plant itself rather then scheduled. If you start light, you are less likely to error. When more of some component is needed, it will be reviled in time. When growing weed, less is best. Grow’m big!


  101. Posted by Rosco cash on June 29, 2013 at 5:59 AM

    This was def a very Insightful read. I have been using a larger in width plastic PVC pipe I made into an extraction tube and a mesh screen instead of coffe filters. And when adding heat to get the butane out I have a grow bulb/spot grow using as a heat lamp

  102. Posted by Rosco cash on June 29, 2013 at 5:56 AM

    Would it be beneficial even to maybe jus try, running a tube filled with just keif? I’m assuming if that’s what is being actually used from the product it could maybe jus produce a massive amount I’m a fraction of the time. Never heard of it tho

  103. Hey what is up great tutorial I’ve never ran fresh frozen run before I’ve packed my three columns and I’m ready to go only question is when I’m repacking is moisture an issue??… Thanks

    • Yes. You don’t want the trichomes coated with ice.

      • Posted by Taylor Fulton on June 28, 2013 at 1:52 AM

        What effect does a slight bit of ice or moisture tend to have on the final polymer? I may be out of place, but for that matter, why do some say that reclaim that’s been through water is bad?

        • The terpenes, including the diterpene cannabinoids are slightly water soluble, so it will absorb and hold a certain amount of water.

          Water speeds up the degrading of the cannabis essential oil, and can lead to mold or rancidity.

  104. Posted by Willbur on June 25, 2013 at 2:40 PM

    HI! So i am planning on doing my first fresh frozen experiment soon and I was curious if you pack your tube with fresh material first and then freeze it or freeze the material and then pack it frozen? I was also curious if bringing the tube from a freezer to a outside temp of 80/90 degrees would make the inside of the tube sweat and in turn extracting water soluble waxes and chlorophyll?


  105. Posted by gilmourofcurtis on June 16, 2013 at 10:43 AM

    Is there any chance you could make a parts list for your pressurized or closed loop sled?

  106. Posted by scott zcollett on June 12, 2013 at 4:34 PM

    Interesting thought could u use sand in a double boiler. I heard this in reference to another application but since i only have an electric skillets sand would be easier for me to use and safer then water. Any suggestions? Tnx

  107. Posted by Richard on June 12, 2013 at 1:55 AM

    how long and on what temp do you have to heat purge to get shatter like oil? i don’t have a vac or chamber and don’t really want to spend the money on one if i’m just doing small runs here and there

    • When we weren’t using a vacuum, we kept the oil under 125/130F in a thin film until the solvent bubbles ceased. Maybe half a day.

      We currently use -29.5″ Hg vacuum in thin films, at 115F.

    • water that is just about to boil and purge around 17 mins cool the dish down and enjoy
      then air purge for a day to get max. shatterness

    • Posted by Jester on June 12, 2013 at 11:38 PM

      I am a 100% newb to this entire subject, and about 90% newb on HVAC (air conditioning), but the pump I have seen used is the same as what I was able to rent from autozone to do the A/C work on my car. It’s fairly spendy up front at ~$200 (not sure exactly what the pump alone costs, b/c I rented gauges as well). Their rental system boils down (pun not exactly intended) to:

      You give them face value for the tool and if returned in 24-48 hrs they refund all your money. It’s a pretty sweet deal that most auto parts stores do with tool rentals, but unfortunately Autozone appears to be the only parts chain that carries these pumps (at least in here in PHX).

  108. Posted by Jay White on June 9, 2013 at 6:57 PM

    Butane bonds to cannabinoids and its terpenoids by means of hydrogen bonds correct? The only way to separate would be to winterize with ethanol or another less volatile polar solvent correct? Also, is lab grade HPLC ethanol good to use?

    • Butane dissolves the diterpene cannabinoids and holds them in solution, but there are no bonds. Butane already has all its bonds full.

      You can simply evaporate or vacuum the butane away, or winterize with ethanol, and let the rest of the butane exit with the alcohol.

      A 200 proof HPLC grade of ethanol will work, though so will 190 proof azeotropic grade. Sometimes they use driers like Benzene to remove the last bit of water from 200 proof, so we even prefer the 190 proof food grades.

  109. Posted by Bobjones on June 6, 2013 at 8:24 PM

    Hey Folks,

    I’ve got a small problem, and could really use a bit of expert advice. I have a crop of 14 plants that are 40 days into their flowering cycle. Unfortunately, the crop has recently begun seeding. My question is, should I immediately harvest my crop and use for BHO extraction, or is there any benefit whatsoever in allowing my crop to continue growing to full maturation? This is obvious a time-sensitive matter, so any and all prompt responses will be most appreciated. Thanks in advance for your support!



  110. Posted by scott zcollett on June 1, 2013 at 8:04 AM

    Im currently making ear wax or dry crumbles, i would like to try making budder next.

    • Posted by frank l jones on June 3, 2013 at 4:33 PM

      here bro need your advice
      Im doing my 1st thermos bho soaked 1 hour
      drained and strained as directions just used 1 oz of prime bud
      it extracted amazing lookin did a hot water bath using tap water
      changed it a few times till bubbles look about right( about 30 min)
      then I heated to boiling my everclear mixed and it turned gold and dissolved
      on the spot,i then strained thru a coffee filter into a jar and placed into the freezer,my plan is to leave for 48 ours
      at that point if I understand im to filter once more placing into a collection vessel? and then use a hot water bath
      or heat pad with temps at 125-140 deg? up to a coulpe of hours
      would it still be possible to vac purge at 115 temps/
      some how ive gotton my self confused
      please ive got about 40 hours down time

      • You can vacuum purge after evaporating away most of the alcohol on a heating pad, or do the whole thing under vacuum. We use 115F and -29.5″Hg for the vacuum purge,.

        • Posted by frank l jones on June 6, 2013 at 10:31 PM

          thank you for getting back to me,so I did do my first run and it did butter on me
          however the taste and affects are as good as ive ever had(smile)
          I discovered that if I placed a pyrex pie plate directly on top of glass range
          set on low this was a stable 134 deg I placed my plate and I did the really newbie thing and it was turning to oil like beading up,should I have pulled it at that point? it buttered reall quick,i was wanting shatter and seemed to miss my mark(smile) like I said Im not unhappy kinda blown away that its
          come this far,the return was around 10 percent still have 1 more chance
          as my last small bottle dwells with in the freezer
          so to make sure ive got things correct do I place the plate with 3/16
          inch deep right into the dessicator? you have mentioned the option of using a hot bath so im wondering will the 114 temps under vac leave me with more terps? im also wondering if I use the 140 temps do I lose terps? guess im more after flavor,so im feeling good with my 2nd try in the am just one more
          question when ya redissolve the bho into the hot everclear how long
          is advised before placing this into freezer
          and bro , thanks a million
          never met such generous folks I do wanna attend your school but will need to wait till winter to do so

          • Yes, it goes into the desiccator and the alcohol is cold boiled away under vacuum. 115F will still leave lots of floral terpenes, while 140 will boil them away under vacuum.

            I stick the jar of oil dissolved in Everclear directly in the freezer and leave it for about 48 hours, before filtering out the waxes.

  111. Posted by scott zcollett on May 30, 2013 at 1:43 PM

    I am getting ready to start using a double boiler when im blasting. I have been doing a lot of reaserch into temperature and was wondering what are good temps for your water, under the pan water and then oil in the pan if it matters with different materials like a pie plate or pyrex. Then i understand you leave at that temp for 3 hours then air cure for 3-4the days. Anything you would like to share with me prior to class would help.


  112. Posted by Cletus the slackjawed apostle on May 29, 2013 at 12:21 AM

    Hello and thank you for this post. First time posting, longtime a reader. First i want to say this is a fantastic attempt at creating a concise and thorough thread concerning the gathering of 420bho related info. I am a longtime fan of the concentrates, and I am also on a personal mission of helping those who medically need these concentrates for their day to day fight versus sickness and disease.

    I have some questions regarding Absolute Shatter. This is the concentrate I myself prefer to make and enjoy. I have Woody Oilmaker to thank, if I could, for his efforts to educate the masses with his quality vid’s. Its through his videos, and this page, and the work of many others and then my tireless efforts of combing the internet and speaking to growers and producers for tips and tricks to produce a high quality Absolute shatter, that I feel good about the product I am producing. To all of you I say Thank you.

    Now for my questions…How can I get my product to people that need the medicine?Im not looking to make a profit other than to keep being able to stay above water in order to help others? I produce butter or oil for cooking, as well as I have refined recipes and produce edibles that taste and look appealing. And my Absolute shatter is the bomb.

    I would also like to get my shatter out to people in the know so that I can get feedback that can be helpful for future batches. No one I make it for has ever had AShatter before, so there is no basis for a comparison and analysis.

    I have read of all the medicinal abilities of cannabis but until I started making shatter I never had experienced any positives relating expressly to helping someones ability to breathe more freely.

    I have self medicated for Inflammatory Bowel Disease for years, but now I find my shatter can help people breathe more freely.

    THAT is my biggest question…When I smoke my shatter, I can within minutes breathe more deeply and freely than before my hit. Is this a result of clean, shatter interacting within the lung membrane, opening up airways because of the medicinal characteristics of pot? Or am I stoned?

    I work hard to refine my shatter, before I winterize, i let my grain alcohol mix sit 12 hours at room temp stirring every couple hours.

    I really want to help if I can, If i thought I wasnt helping anyone with my attempts…I would be willing to just continue to make for myself and my friends.

    But I would like to help people who i can trust and need some help.

    Any thoughts would be great, Again I think you for the forum and If you could use a future helping hand in any endeavors with this website, blogging, or otherwise please contact me.

    Best regards
    Cletus the slackjawed apostle

    • Cannabis essential oils are a bronchodilator, which open up the lung passages and promote easier breathing.

      Some of the constitutes are also expectorants, which help clear out any COPD obstructions.

      One of the best forums that I’ve found for distributing our extractions locally, is aka PIF. It is where we donate our surplus and if you are in Oregon, more help is always appreciated.

      • Posted by Cletus the slackjawed apostle on June 6, 2013 at 12:37 AM

        I just completed another run of SHATTER and I used Bacardi Rum 151-proof instead of my traditional Everclear, I was wondering if moonshine would be better?? When it comes to winterization, is the bottom line always what grain alcohol has the highest Proof?? Thank you in advance….
        Cletus the slawjawed apostle

  113. Posted by C4h10 on May 28, 2013 at 1:28 PM

    I’ve been making BHO for awhile now and I’ve always wash out my BHO Pyrex’s with ISO to get the oil out of the corners then I let the ISO evaporate so it can be smoked. It seems as tho when I re dissolve the BHO with The ISO it purges the BHO without using a Vac. my questions are is it safe to re wash BHO with ISO? And is this really releasing all the butane?

  114. Posted by Derek on May 25, 2013 at 5:55 AM

    Forgive me if this is a stupid question,
    I recently starting smoking BHO, and have noticed something that has brought me here. I have been smoking herb for at least 5 years and never had much of an issue. But when i take a Dab after work or whatever i notice the corners of my eyes or head tend to slightly twitch, not like a tick, just a slight muscle spasim. Has anyone else had this? Could it just be relaxing muscles? I would just like to compare with someone.. Thank you

    • No spasms or ticks here. Anyone else?

    • Posted by Dayzty on May 25, 2013 at 10:37 AM

      I’ve had that happen to me a few times. For me it was just nerves relaxing after a long day. I do computer work, so my eyes sometimes are a bit strained, and bho (as well as a strong joint) will have this effect as it’s sedative effect forces me to release that built up stress.

    • Posted by jon on June 6, 2013 at 4:54 AM

      I’ve heard this can be related to dopamine systems. Hopefully not the honey.

  115. Posted by Matt on May 22, 2013 at 8:33 PM

    Thanks for all your hard work!

    I just have a few questions. Have been making BHO via glass extraction tube (small) using dried and cured bud usually doing small runs around 2g-3g, yielding anywhere from 10%-22%

    1. I have never frozen my bud before I blast. Living in a warm and humid climate would freezing my bud before help in any way?

    2. should I grind up my bud for extraction? I normally just slightly break up my nugs to fit in the tube.

    Also, seeing your URL by any chance do you have formal training from a University or have you figured out all of this wonderful information through trial and error?



    • We only freeze fresh cut material for BHO extraction, or dried material for alcohol extractions.

      Grinding increases packing uniformity and density, but lightly breaking up by hand produces less green color,

      Our group’s training hails from Oklahoma State, Portland State, Oregon Institute of Technology, and University of Washington, but most of the information about cannabis was through physical and on line research. Not much in the college text books about cannabis extraction or formulation.

  116. Posted by scott zcollett on May 14, 2013 at 1:21 PM

    I just had my bho product tested in a lab and it came back at 88 percent thc. Whst is the average that you all normally see.

  117. Thank you first of all, you have the most in depth site on extraction methods. I have been studying and experimenting with making the safest BHO I can so patients don’t suffer. Where I live far too many people are cutting corners at the cost of other peoples health. So my question to you is I have been using butane to pour through a glass or stainless tube into pyrex just like most, and I want to make something better than your average honey oil. Its been lab tested and it was one of the labs only oil to pass their solvents test. I just don’t have the access or the finances to work with the equipment you are talking about. There is so much information on here my head is spinning. Maybe you can tell me what your opinion is on the different extraction methods for gaining the highest THC and CBD potency, and also best way to reach absolute or an oil that will actually retain the wonderful smells and attributes that led me to pour that strain in the first place. Sadly, the highest grade alcohol I can find around is usually just 91% is what I was taught with for helping with the purging process. Like I said I’ve been reading your site for days and my head is spinning so if you can make any sense of that I would love to improve. Thank you and I hope to hear back. It is nice to see some people taking this to a place where it can help people. BHO has been so controversial that I would love to be better. I would honestly love to come to one of your classes or seminars I read about. I have chronic pain for life from a fractured calcaneus and a shattered foot so everything I have read about opiate withdrawl and pain management is amazing. Thanks again.

    • We get the highest potency using a non polar solvent, like propane, butane, pentane, or hexane, and winterizing it to remove the non active waxes using a polar solvent like ethanol.

      Have you tried ordering 190 proof from ?

      Love to see you in class. We currently have more out of state students attending, than Oregon students.

      • Thank you. I read much more of your site and did a lot more research and decided that I like the fact that butane extracts the least water soluble biproducts . I made some drastic changes to my process and was left with the most pleased results i think ever. I used to pour over a dish already on heat to speed up the purging process but i was losing all of the terpene quality and decarbing way to fast, for one of the first times even as it still had butane bubbles, it reeked of the strain I used. Im looking forward to your suggestion because i think the winterizing was the last step i was missing. Ill just have to be patient and get the right grade alcohol or ethanol to do it right. Thank you again. I really appreciate the info and Im serious about signing up for your classes so hopefully i will get up to Oregon. Like I said this is something that I plan on using to change my life. Thank you.

        • Thanks for the good thoughts bro! Look forward to seeing you in class!

          • Hello GW,
            I just wanted to thank you for all of your help. I sadly after reading more in depth about the LLC as a whole and the classes and their specifics, I can not attend. I am not a medical student, I would love to be but I don’t think it is in the cards. I can not express how much I appreciate the help as I said before I want to make something as high/medical grade as you describe but I don’t have the access to some of the items you use. But, I am pretty clever on my own and with a little guidance from you, I have been making shatter with the goal of getting it as close to absolute as possible with the equipment I have for a while now. I have just done loads and loads of research, and then seperated out all the people that really don’t have a clue and finally found your website, and haven’t closed it for like a month. I wanted to come up there for a very similar reason as to why you seem to be doing what you are, so the patients in the area where I live and are a part of the community, aren’t going to their local Dispensary or wherever and buying products riddled with cancinogens. They have safe access to safe MEDICINE! I love that your meds are free to the patients and that you can use this as a catalyst to do amazing experiments with extraction and be able to have the access to have patients to give you direct results, not to mention all the people you are able to help. So it really took the wind out of my sails to find out I am not eligible, but I feel after reading your entire site a few times and getting to correspond with you I have a pretty good feeling. Sorry for the long post, I just knew I wouldn’t get a chance to thank you in person now. So I think I really just have one or two simple questions for you. In my original post, I asked you what your opinion on the different methods were and that was far too vague. I really wanted to know of all the non-polar solvents you listed; hexane, pentane, propane, butane, etc.
            1) Is there one that you prefer for highest yield in weight and potency, for either THC or CBD’s and CBN’s using almost always cured materials?? And I understand you can achieve different levels of different chemicals by decarbing at different temperatures, because I understand they all have different applications. I have always prefered butane extraction and used 91% to wash, I am finally getting the right stuff to winterize, but anyways using low heat I always simply purged the resin of contaminants and also dehydrated it to the point of shatter.
            2)Keeping in mind Im planning to winterize when the materials arrive, is there a better way?
            3)Lastly, I just was wondering when to introduce the ethanol. So it sounds like I dissolve the oil into the ethanol after it has finished cleaning with I believe it was like a 10:1 ratio and then freeze for 48 hours and strain through coffee filter, correct?
            Again, thank for your time, it is a privilege to get to interact with other people with such a passion for helping people. Peace, Joseph.

          • Thanks for the good thoughts and sorry we won’t be meeting your smiling face!

            We mostly use butane, because it does a good job and with recycle, it is the cheapest method that we’ve found. Hexane also does a nice job, but is more expensive and more work to purge.

            We winterize with 190 proof ethanol, which works better than Iso for that purpose.

            We pour in the heated ethanol as soon as the bubbles stop, with the BHO extraction sitting in a hot tap water double boiler bath.

            Mixing the BHO extract at about 10:1 with alcohol and freezing for 48 hours before filtering out the waxes, using a coffee filter, is correct.

          • Also PLEASE post any updates you have with pain management and opiate withdrawl, as I thought that was extremely useful and I would love to pinpoint an oil to help me. Thanks Again.

          • Thank you, I know everyone says that, but I truly appreciate the sound reliable advice and respect the words and work you are doing. It sounds like I should have a pretty pristine extract with the ethanol. I had one idea to run past you, I was pouring and Im sure you know that whatever collection dish you are using it is going to be extremely cold from the negative temperatures being poured out. I was just trying to be creative while I wait for my winterization materials, and thought as I introduced the alcohol almost immediately after finishing pouring the bho and mixing quickly and thoroughly I saw tons of clumps form under the cold temperatures and the reaction. Could I strain that immediately after to extract a portion of the fats and waxes caught in the winterization process? Or is this something else entirely? They were evenly distributed white clumps which I know I have read about in someone elses post but I was just wondering if I was quick about it, could achieve a better extract? Thank you, Sincerely, Joseph

          • We always filter both before and after freezing when winterizing. We are able to strain out some of the waxes immediately after re-dissolving in alcohol, but it takes colder temperatures and time to fully winterize the material.

            We have the most success after about 48 hours at around 0F.

          • Thank You once again. Of course I only meant this for the meantime while shipping feels like an eternity. Because of my recent surgery, Im just relearning to walk this week so Im sure Im just being impatient. This, I can do anytime. So I saw that you said that you heat your ethanol before introducing it into the oil: 1) what temperature do I heat to? 2) I will look up the evaporation heat and rate for ethanol but I imagine you would heat it right before introducing it so as to not evaporate the alcohol too fast or too early, is this correct?? I would think with a 10:1 ratio you would be fine. I just haven’t done it yet so I wanna make sure I get it right and it’s strange to strain an oil. Im very excited. Best wishes to what seems like a great group of people!!

          • I just heat it somewhere between about 140F to boiling, as it will cool down rapidly when it contacts the oil and the container. You can dissolve the oil in cold alcohol, it just takes a long time.

          • Hello GreyWolf,
            A few last details. I feel like planning is your best friend in this case. 1) Is a flat electric pancake skillet with a buffer in between the skillet and pan the best way to boil off the everclear after straining and reintroducing all the oil/alcohol mixture. I feel like thats how I have the most control over temperature and the ability to get to a specific temperature. I’ve seen people do some scary looking setups to heat their mixture. 2) With raising temperatures up to 175 degrees F or above to start the evap. process, will most of my terpene quality be destroyed because I’m breaking my usual temp. threshold of about 80degrees?? Lately more like 90/95degrees or so and I honestly only go that hot because the summer is upon us and its simply that hot or hotter. 3) At whatever stage you introduce the everclear, isn’t that going to bring your butane purging to a halt because of the low low temperatures you put the oil/alcohol mixture in? I was just thinking, should I let the oil go for a few days on low heat before introducing the alcohol to get the cleanest shatter, or does any residual butane get released when you boil the alcohol off?
            Sorry for the long posts I just always think of the little details and I want to make sure I have them covered. 4) Have you had these essential oils you make tested to see what percentage of solvents IF ANY are still left. I just simply find everyone calling there stuff ABSOLUTE Shatter. But what I truly want is CLEAN CLEAn

          • I like a hot Canola oil bath for the best temperature control without local hot spots. I use an electric fondue pot to control the temperature of the oil and a laser thermometer to keep track of the temperatures.

            Yes, you are boiling off the monoterpenes at 173F, along with the alcohol.

            I pour in the Everclear as soon as the butane appears to be gone. The rest of the butane will leave with the alcohol.

            We have a GC and test our own oil for content. There is no issue with purging residual solvents below levels of concern using just heat, or heat and vacuum.

            There is also no problem telling with just taste and smell whether you have residual solvent present at any levels of concern. We can taste and smell the alkanes and alcohols an order of magnitude lower than the levels NIOSH found them to be insalubrious.

          • Ok, Thank you again. That is beautiful that you can test your oils on the spot for contaminants. Anyways, I guess I thought skillet because I was thinking of putting it back into the 13×9 trays and using a skillet simply because of the surface area, but if I am going to lose those terpenes anyways I can use a setup more like what you are talking about. I remember it from the website. 1) So using pretty fresh material, like a month old, is it possible to winterize and boil off the alcohol and still be able to control whether you have the taste, smells and effects that you want? I just don’t typically purge at that temp unless Im trying to achieve a certain affect? Peace and Have a wonderful day!

          • You lose some of the monoterpenes when you boil off the alcohol, because they are alcohols, ketones, aldahydes, ethers, esters, etc, with a high vapor pressure to start with.

            If you vacuum purge at a low temperature, you can preserve more of them than if you purge the alcohol with heat. You can make an oil that smells and tastes like the original material that it was extracted from.

          • Greetings!
            I was wondering if you had a recommendation on a vacuum purging system and the right specs I want to look for as far as CFMs and all that? I have never vacuum purged simply because I got busy but with my new found time with my injury and my passion to learn more about this I figured I would get one. It seems like that is another way people are achieving very good results in making shatter or taffy as well. If you have any ideas on a good setup please let me know. Thank you.

          • We’ve had good luck with all of our vacuum chambers so far, but if you have the funds, I would go with a vacuum oven big enough to hold a dish the size you will be working with. Not sure who has the best deal, as we bought a used Napco and completely rebuilt it, including new digital controls.

            I can tell from the design, that the Napco wouldn’t hold the required narrow dead band, with the existing heat strip arrangement and mechanical capillary tube control.

            From a controls standpoint, it needs a narrow dead band and needs to be controllable from ambient to 300F. Plus or minus one degree F is reasonable. After rebuilding and upgrading the controls, ours now holds dead on at plus nothing, minus nothing.

            The other end of the spectrum is a DIY, like the one we built at

            I would pick up a single stage vacuum pump in the 6 or 7 cfm range. A smaller one will work, but the speed of the larger ones is handy. We’ve used our CPS VP6S pump reliably for about five years, so you might take a look at them.

            You don’t need a two stage pump, as you don’t want to vacuum below about -29.5″ Hg, because it boils away the cannabinoids.

          • See, I knew I asked the right man! Many thanks! You always seem to steer me in the right direction. And now I can use those specs to get exactly what I need. So the CPS VP6S pump, 1) would I simply create my own chamber and use parchment or some type of wax paper to put the concentrate on while it purges? I can see why the bigger chamber is so nice. User friendly it sounds like. Again Have a Wonderful Day and Thank you!

          • Yes, you can use parchment paper or a silicone rubber pad, as well as a shallow dish to cold boil.

          • I just wanted to let you know what a profound effect your website and its information has had on the Northern California Region. I can’t speak for everyone, but the people I talk to have heard of this site and you seem to be some what of the authority on how to correctly make concentrates. And in turn I have been able to change some people’s minds about essential oils and I am able to present them in a safer, more medicinal, more user friendly, more aromatic, more scientific light. Breaking down the science for people is sometimes the only way to break down their closed minds. They need facts I guess. So again, Thank you from the bottom of my heart to all of you there that sit and read my long rants and still take the time to reply. I hope you know you change peoples lives. Peace, Oh and thank you for the vacuum recommendation, My New Project!!!

          • Thanks for the good thoughts Joseph and you’re welcome! You can repay the favor by passing on any portion of it that works for you on.

            Good luck with your new project!


      • Posted by Drake Snow on June 5, 2013 at 11:10 AM

        Dear Mr. GF,

        Recently, I stumbled upon the most interesting of sorts with what I am about to ask if I can redeem this or not? My material so happened to fall in bag mind you, near a dryer sheet. The material was near this dryer sheet for about 2 weeks. I did not think much about it, because I had mixed that specific material with other of the same material that was stashed elsewhere for blasting. I have used your thin film vacuum purging technique since February of this year. I usually place a little heat underneath for speeding of purge. Thus, I did so with the material I had mentioned before. However, after 30 minutes of vacuum purge at 90F and then a little more with an additional 15 minutes, plus trying to place in freezer over night inside petrie dish for speedy drying.

        I still taste the damn dryer sheet in my oil!!! What am I to do? Is this something that you have ever heard off? I want to purge it out without killing the floral notes or the oleoresins/terpenes. I can taste the delicious taste in the back of my palate, but it is on the exhalation that I sense the dryer sheet taste and this is even filtering through water, mind you.

        I do not know what to do? Should I purge it some more? What can I do to get that dyer sheet fragrance taste out of my oil? I feel awful about it. It would have been delicious if it had not been for that 10g’s of material that was left inside a bag which was inside a vacuum sealed bag near the dryer sheet, this oil would have been outstanding like the last few oils have been due to your amazing simple process…

        Please GF. If you think I can salvage this by any means? I am here to learn! Please shed light on what I can do, if I can do anything at all?

        Thank you in advance.

        • Wow, dryer sheets are potent! Using dryer sheets is actually how women tell other women that a man is taken. What bachelor ever uses fabric softeners?

          Sorry I don’t and Joe doesn’t either. Any process known to us, would also remove the lighter terpenes.

    • Hello Again,
      I hope all is well! I have a quick winterization question. I started to pour the 190 everclear in the somewhat purged but still liquid stage. I had seen someone do this and get a wild reaction. And being my first attempt I figured I might make a mistake or two. But I had quite of bit of research and it often conflicts itself. My question is 1) when I poured the alcohol in it seemed to be evaporating faster than I could pour. or is that simply the butane evaporating and the alcohol taking its place. I Put the whole thing in the freezer then was able to add it much more freely. Now After over 48 hours at 0degrees or below i just have alot of little white things floating. I understand Im trying to strain out the fats waxes lipids etc. but I just wanted to see if this was right before I take it out of the freezer. 2) Should I have waited longed, closer to the oil state before adding the alcohol. 3) Also if so, could i take it out and let the butane evaporate further and then redo the process if necessary. Thank YOu so Much! Peace

      • After 48 hours, you should be able to filter out the wax and lipids.

        Adding the butane early is no problem, as it will leave with the alcohol.

        I would just filter it and vacuum or evaporate away the ethanol.

  118. Posted by jozikins on May 9, 2013 at 11:23 AM

    Hey guys, this is a great read, great attitude!
    Question: I was looking into Hexane extraction, but because of the price of Hexane I was looking into alternatives. Calibration Gas is 40% N-Hexane Gas, and background gasses are N-Pentane, Oxygen, and Nitrogen. I know that Hexane and Nitrogen are excellent for extracts, Oxygen I’m not worried about, but what about Pentane? You egg heads have any insight?

  119. Posted by JackFlash on April 29, 2013 at 12:54 PM

    Hi Greyfox. 1st I’d like to express my gratitude for your openness & willingness to share reliable info. You are obviously highly competent & I love the creativeness of all your projects. I have 2 questions & I value your opinion. Hope you can help.

    1. I plan to set up 3 – 36″ SS columns & use your BHO extraction method. Freezers capable of -32°C/0°F & large enough to contain a 36″ column are financially impractical for me. What do you think of using a 4 ft long x 8″ dia sched 40 PVC pipe with push-on caps filled with dry ice to freeze the columns? I’d drill a pressure relief hole in one cap. Will I damage the product with the extremely cold (-78.5°C/-109.3°F) temps? If this is a problem perhaps I could put a scrap piece of SS pipe filled with old material with a lab thermometer inserted in the middle into the dry ice & remove extraction columns when they reach ~ -10°F. What do you think?

    2. In the interest of saving time & perhaps a little butane, I’ve had both ends of my SS columns threaded. After the 1st run of each column, I plan to reverse input/output ends, put columns back in dry ice to chill & do 2nd run with reverse flow. Do you think this would be an effective approach instead of repacking?

    • My wife mate Grayfox thanks you for the good thoughts bro!

      Dry ice temperatures won’t damage the cannabinoids, but it will dramatically slow down the process.

      Are you freezing the columns to run fresh frozen green material or using it on dry material?

      Reverse flow is a good compromise, but won’t usually give the same return as a complete repack.

      • Posted by JackFlash on May 1, 2013 at 9:14 AM

        Thanks for the feedback GreyWOLF. Sorry bout that!

        I’m running fresh dry material but plan on trying the green next time around. I will use a lab thermometer as I described in the 1st post to keep the temperature between 0° & -10°F. I’ll try both reverse flow & repack & post the difference in results if that’s helpful.

        I also found an old SS 2 qt thermos. I put a handful of flint chips in it & put it in a tumbler to clean which worked well. I’m going to try the thermos method as well using dry ice & an infrared pyrometer to control temperature. I’ll post the results & anything else that might prove useful.

        Again, thanks for your help & for being an invaluable source of info.

  120. Posted by adam on April 27, 2013 at 1:37 PM

    hey got a question greywolf so i come across material that blows gold but once in vac oven goes darker after a few min of purging to honeycomb. I like you host medical patients, i run uhp u butane so on. I am no first timer just bouncing ideas from one co op owner to the next. thanks brother

  121. Posted by Josh B on April 26, 2013 at 12:14 PM

    I need help , I have spoke with Graywolf on another site in the past(which I no longer have access to) , but my father inlaw was getting his cannabis oil from someone other then me at the time .. he has cancer , already went thru chemo once and now the tumor is back and bigger then ever , the Doctor’s gave him 6months to live , but want to double his amount of chemo in hopes it may help ..

    For aggressive cancer treatment how do I convert the BHO into something I can put into a capsule ? Just decarb it ?
    What temp and how long should I heat the BHO to properly decarb it so it can be taken orally ?
    Where in the PDX area can I buy empty capsules to load ?
    What dosage of BHO (far as weight per day) should he be taking ? (Ive read starting with a size of a grain of rice ramping up to one gram per day)
    Or is BHO the wrong method here ? Maybe I should be extracting with a different solvent ?

    I really love the idea of the HAO , but during the chemo his taste buds freak out to the point he can’t stand the taste of anything , so that’s why I feel an oral capsule is going to be the best bet

    Thank you , Josh

    • We decarb oil at 250F until we reach the stage of decarboxylation we are seeking. See
      You can put decarboxylated oil in a capsule, or better yet mix it with about 30% coconut oil to help uptake and tie up the liver. We then mix that with cornstarch to stabilize it into something like silly putty and then stuff that in caps.
      Most health food stores have O and OO gel caps. I got my last bag at Natures.
      The standard Rick Simpson cancer dose is 1 gram a day, broken up into three or four doses. We start patients with unknown tolerance at 50 mg, to see what happens and then titrate upward to reach the desired dose.
      That is half the 100 mg dose we’ve found to be about an average low tolerance dose for pain, with 200 mg about average, and 300 mg a high tolerance dose.

      • If a person didn’t want to get the high ,etc effects but just needed the THC for cancer wouldn’t shatter or preshatter taffy be a good addition to the full plant extract “rso” style? I am curious because it is hard to get enough “rso” into people without them getting too high. Although in my experience they all claim that after a while it doesn’t effect em that much but,,,,,,,,,, Just wondering if you have any experience blending it together. Would the undecarboxilated THC still be usable by the body for the cancer or would it need to be heated before it would become active against the cancer?

        • I don’t know the answer to that question, but there are folks juicing raw carboxylic acid cannabinoids and reporting good results, so my best guess is that it would do something positive, even if it weren’t the panacea that you are looking for.

          One thing that THCA can’t do readily, is pass the blood brain barrier, but that only prevents it from reaching the CB-1 receptors, because our immune systems CB-2 receptors are scattered throughout the body, and so the CBDA present has full access. They are also finding more new cannabinoid receptor types scattered throughout our bodies, and they may also be involved.

          • Posted by c on May 9, 2013 at 3:50 PM

            amazing times. I know of many people doing the raw plant juice and they all have had great results . The “shatter” is just more of that kind of THC accesibility to the body. Course the shatter doesn’t have the fresh other stuff that comes right out of the plant but that would be in the “rso” already to some extent. Interesting stuff for certain!

      • Posted by Josh B on April 30, 2013 at 1:32 PM

        Thank you very much for you reply , I will follow as you suggested with coconut oil and cornstarch ..

        Would you suggest using butane or 99% iso for the extraction ?

        I don’t know if it’s true or not , but I read that iso will extract cbd’s where as butane will not ,or not as well is maybe what I read ..

        If I am leaving my questions in the incorrect area of the site please let me know

        Thanks , Josh

        • Both butane and Iso will extract the CBD, but we use butane and ethanol for our oral meds.

          • Posted by Josh B on May 6, 2013 at 3:07 PM

            What percentage of corn starch is normally used to achieve a thicker state ? something like silly putty as you refereed to ?

            Using a stainless steel cup I submerged 42 grams of vac purged bho into 250deg canola oil , took 10-15 minutes for it to stop bubbling after it was heated.. I let it cool down to about 100-110deg’s and added 12grams (30%) coconut oil ,after that I began to add corn starch , got up to 12grams of corn starch and it still wasn’t changing the viscosity any thicker ,I tried adding heat to see if the corn starch would react/thicken the mix and it did not (200-210deg’s for a couple minutes).. I just grabbed a syringe and filled the capsules

            I’m thinking I’ll just skip the corn starch in the future batch’s, or try it on a smaller batch next time . is there any advantages or disadvantages – besides changing the consistency – in adding or not adding corn starch ?

            Thank you so much for helping us out with this , putting the info out here for us all to use is a true blessing !

          • 35 grams of our silly putty consistency, contains 10 grams oil, 3 grams coconut oil, and 22 grams of cornstarch.

            That makes the cornstarch 62.8% of the mixture.

            42 grams of BHO would use (4.2 X 3 grams) of coconut oil, or 12.6 grams, and (4.2 X 22 grams) of cornstarch, or 92.4 grams.

            Adding the cornstarch just keeps everything more stable for travel, so that the caps are much less likely to leak.

  122. Posted by M C on April 19, 2013 at 2:32 PM

    What about freeze dried material?

  123. Posted by matthew on April 15, 2013 at 11:42 AM

    Your article and the others on your site have been very informative. i just have a question about a current batch I made. I used dried plant material and ran it through a glass extractor with power 5x butane and two coffee filters at the end. i have been having success with this and have been using heat purging in hot water on an electric range and have been getting nice, rock hard concentrate that can be easily handled. however this time did a bigger run than normal but cant seem to get the oil to the hard stage this time. we have tried vac purging as well as heat and somehow cant seem to get it to what we have done all the other times. what do you think could be the cause of this and how can it be corrected?

    • Retained solvent or partial decarboxylation.

      It takes more heat and time to purge in deeper pools, so more may remain. The added heat decarboxylates the oil and makes it more runny.

      You might consider purging in smaller quantities or in a larger container, with more surface area.

      • Posted by M C on April 16, 2013 at 12:20 PM

        Ding ding ding! I had the same kind of thing going, great bho, then bad bho, much hair pulling, thinking, asking, etc and a month of bad batches I came up with three things that are pretty key
        -the depth of the pool.
        I was killing myself trying to crank through 4-6 columns then purge all at once. I noticed a batch could be under vacuum for 6 hours, be flat w/ no bubbles, but tip the container so the batch runs, and whammy, bubbles. Too thick
        -Dry source material. No, really dry. A friend related that he packs his material away with large bags of dessicant he makes from bulk for a week or more before running it. So now after the screen, right before I run my material, I toss it in the oven for a little while (like toss as it warms, not throw in and leave) then pack in a tube.
        -Quality of vacuum. I was pulling down to -29 hg but I was also loosing pressure very rapidly if I flip the valve to isolate the tank. What that means to me is that the pump is pulling outside air and whatever through the tank. Not going to be thorough. When I worked out my lid gasket deal better, I noticed the pump quieted down a lot, no rattle, and could run all night without getting really hot.

        And do yourself a favor and put a vapor trap between the pump and your pile of profit. Things go wrong, pumps (cheaper ones) will leak oil back to the vac chamber while you wait for depressurization. Make Hulk Angry.

        • Posted by M C on April 16, 2013 at 1:23 PM

          And I still want to come visit, take a class, rub brains and see what happens, but I still have a wildfire for a life, can’t really make it happen yet….
          Side note..
          Making a new vac tank, I had on hand a 2021 stainless bowl 22 in dia around 12 g, and recalled squirreling away a round plate of glass 1/2″ thick, with holes predrilled for hanging the thing. As the plate is larger than the bowl, I could hang 2 holes off the edge and only have one exposed to vacuum, so I set the valve/vac line to that. 3/8″ neoprene gasket contact cemented to lip of bowl, put them together and see how it works….rrrrrrrrrrrrrrrr
          hmm, looks like it is pulling vac pretty fast, looks goo
          which is not what the plate glass imploding into the bowl, upwards since it was on bottom, then all crashing to the floor while I stood next to it in shorts.
          I like Implosion better than explosion. I can still walk.
          Why for it go boom?
          the holes in the glass were left rough, not polished out. any roughness to glass is a micro fracture, weakening the entire matrix. And the vacuum says, “Grrrr”.
          Sometimes you just want things to work so you ignore what you already know, I guess?

        • Thanks for sharing bro!

          Really dry material sidesteps water soluble issues, but makes the materia brittle and frangible. We prefer to run at about 10% water content minimum for oil to be decarboxylated.

          For more floral vaporizing flavors, we extract closer to 25% water content, because the lighter terpenes evaporate away with it.

          For the most floral flavor, we freeze fresh cut material and extract it frozen.

        • Posted by frank jones on May 6, 2013 at 7:32 PM

          so could you recommend a vapor trap? size and where to make purchase
          seems im putting together my own lab(smile)
          thank you

          • Posted by frank jones on May 6, 2013 at 8:10 PM

            While we use 180F to vacuum purge a raw oleoresin, adding heat isn’t necessary when thin film vacuum purging raw oleoresins redissolved in ethanol. The alcohol will boil away under 28.5″Hg at ambient temperatures, as will the water that is left behind, even without adding any heat.

            hello Greywolf
            1st I wanna thank you for sharing such as craft,i live in Colorado and
            Im seeing prices soar 2 years ago we were paying 25 bucks a gm for co2
            honey oil 15 bucks for full bubble melt,now everything is twice that price
            Im not sniveling just trying to convey my thankfull ness
            so im a newbie at extraction s I do have a medical garden ,thanks to you folks im now gonna be able to make my own,
            if ya don’t mind id like to hear you elaborate on how to operate a dessicator and pump you mentioned that you control the vac for a half hour or so then lock it down and continue under heat
            does this mean pump is running during the controlled period to observe
            the bigger bubbles then you shut off pump and keep it under vac?
            there are so many utube videos but no one seems to include details
            also im wanting to try out vaccuming ethanol with out heat
            hope this isn’t a pain to ask of ya,it seems im understanding most of
            your info . Im also building the diy stainless dessicator and about to order
            the filter gear and should be on the road soon
            thank you

          • Once you have pumped the system down and it is stable, you can close the valve between the pump and the desiccator and the pressure inside the chamber will stay relatively stable, rising only in response to the boiling going on inside.

            During the periods of slow pressure rise, the pump is over kill, so as soon as you close the valve, you can turn off the pump. Periodically turn on the pump and open the valve to vacuum off any accumulated purged gases, before repeating the isolation and shutdown procedure.

            Do remember to turn it on before opening the valve again though, as it can spray oil from the pump into your chamber and product, if you suck air backwards through the pump.

            Yes, I just watch the bubbles to tell the difference between solvent and fizzy C02 bubbles. The solvent bubbles are random sized, with some quite large, and the CO2/Terpene fizzy bubbles, are relatively uniform and smaller.

            If you cold boil alcohol, you will need a cold trap between the chamber and pump and/or watch your pumps crankcase level like a hawk, and change it every time it reaches max level.

          • I’m still working on our cold trap bro, but should have the final part this week.

            I’ve had only limited success in the lab using dual cold traps and dual condensers running ice water, so how well this works remains to be seen.

            What I did, was order a refrigerant recovery pump after cooler to go in front of the vacuum pump, to cool down the alcohol vapors enough to be captured by the cold trap I’ve made out of a sanitary spool and a lid with one vacuum port and one dip tube port.

            The incoming stream will be pulled through the after cooler, then the dip tube side of the cold trap, and then out the vapor port, to pass through the pump. I can determine what vacuum pressure it will support, after I see how low it gets the temperature of the stream at current flows.

            Obviously the after coolers could be cascaded, and there can be multiple cold traps, or the bath temperature could be lowered by using antifreeze.

            More on the assembly, after I try it out.

      • Posted by Kerr on April 30, 2013 at 6:56 AM

        This could also be the product of excessively dried material. The cannabinoids partially break down from theircarboxylic acid state, leaving you with somewhat decarboxylated material to begin with. This will result in gooey bho.

          • Posted by frank jones on May 16, 2013 at 10:40 AM

            thanks Bro
            so as I was a sayin(smile) back to the thin film purge of butane extract
            redissolved in eth that it needs no heat,Im stuck on cold trap,so my question is (in photo of diy cold/vapor) what size are the flask being used?
            and I do notice a filter there as well so,if ya get a moment sure would
            like more info(smile),and thank yas for such kind offerings

          • I am in the process of building my latest cold trap version, after having experimented with using the original 6″ X 6″ Mk III butane storage tank for a trap, with a refrigerant after cooler in front of it, and both submerged in an ice bath. It works OK, but still doesn’t catch but about 90%, and slows down the process from the added resistance, so larger diameter tubing in the chilling coils are required to reduce resistance, as well as colder water or more chilling surface to capture more solvent.

            My newest version is based on a 6″ X 12″ sanitary spool, and instead of having an after cooler in front of as a pre chiller, the cooling coils are inside the cold trap and I am going to circulate ice water or antifreeze through them. I expect it to collect a higher percentage of the alcohol, and be faster than the current test sled.

  124. Posted by lvzy on April 7, 2013 at 10:33 AM

    thanks for the great information.
    I use a griddle to heat up the inside of my chamber to about 110F.
    drop in my parchment paper with the concentrate, and purge till there is no movement.
    I was wondering why my concetrate seems to have lost all its taste and flavor.
    I have had plenty of runs without vac purging and tasted and smelled great.

    • Possibly the no movement part. We vacuum purge at 115F in a thin film until there are no solvent bubbles present, but remove it while there are still CO2 bubbles coming off. If you cook it until it is bubble free, it will lose many of its lighter terpenes.

  125. Posted by Carson on March 30, 2013 at 11:00 PM

    Where I live, there isn’t any lab testing or high standards for concentrates. Most is sent from out of state and not properly purged. I started making my own after learning a lot off your site about BHO safety and proper procedures. Just wanted to make sure there isn’t more I need to do in order to achieve a clean absolute.

    Process: After spraying butane through an unbleached coffee filter into a pyrex cup, I wait until most of the butane naturally evaporates away and then right before I get magma sludge I pour in a 3:1 ratio of 190 proof alcohol to oil. I wait until all the butane bubbles are gone, then freeze mix for at least 24 hours. Pour through another unbleached coffee filter to trap solids then evaporate alcohol in pyrex tray over steaming pot @175 F until sap becomes flat and hardens. Scrape n enjoy?
    I’ve been diggin the process so far, but with everything you know about solvents and extractions, I just thought i’d ask to make sure.

    Thanks for your help!

    • The proof of the pudding is in its taste and effect. If it tastes good and works, you have a winner!

      A few differences in our processes:

      I add the alcohol hot, after all the observable butane is gone.

      I use closer to 10:1 alcohol to oil ratio, but don’t measure it, just put in enough so that it is still easily filterable once the temperature is lowered.

      I filter before and after winterization, using a coffee filter or Wattman #1 lab filter with vacuum assist.

      175F works, but you can preserve more carboxylic acid closer to 140F without vac and 115F with.

      If you are using it for oral, I would use 250F, and decarboxylate at the same time.

      • Posted by Arturo Gomez on April 3, 2013 at 11:14 AM

        I need help! I am not decarbing my buds. I did not know about your methods until I stumbled on your website one day and have tried to learn as much as I can from you. Which so far I have been very gracious for and I appreciate the time you took to make it happen. I use Luciene butane. I use a glass extraction vessel. I wanted to know once I blast into my dish, I add hot ethanol? What temperature? I have a glass vacuum desiccator with pump. But I have just been breaking buds and packing them tight into glass vessel. I use a 200 micron mesh filter and use an unbleached coffee filter with clamp. While I allow for the butane to evaporate as much I have in a pyrex dish, I have not used hot water bath from the tap as you suggested, the last time I did my blasting. Not thinking about condensation or anything for that matter…I have to say you have shed some light. However, I am a little confused about the purge process. Why add alcohol? As of now, I just wait till all noticeable bubbles evaporate and then I scrape to place unto parchment paper where it fits into a petri dish top. I place entire glass chamber on a flat skillet, due to its best precision in heat. I purge until all bubbles are gone. But even at low level temps and so forth, I still feel there is residual residue in my oil and I am not content with it. So how does alcohol affect your purging process? I understand that I would purge the oil and alcohol together? I am trying to figure out how to make my oil proud. What do I need to do to make my oil the best? Do I decarb before packing it into my extraction vessel? Do I add hot alcohol to the extracted material just enough to cover the surface area? Do allow for evaporation to occur then or do I just go ahead and proceed as I usually do by purging out the gases after extraction without adding alcohol?

        • Adding alcohol is an option, but not necessary. We wash out with alcohol, because we are going to winterize the oil to remove the waxes.

          We heat the alcohol to boiling before pouring it in, but it cools down immediately. You can use cold alcohol, but it takes more stirring and agitation to get the BHO to dissolve in it.

          Purging the alcohol will remove the residual butane, by forming an azeotrope with it, as well as stirring the puddle to aid in the butane molecules escape.

          It works best for us to decarb the oil after extraction, because you can tell exactly what is happening, by watching the CO2 bubbles.

          We are adding alcohol to the extracted oil at the ratio of about 10:1. It needs to be thin enough to filter, at around 0F.

          • Posted by funkmecca on April 4, 2013 at 11:10 PM

            Ok, so you decarb your oil before you add your hot ethanol and then you winterize? I am trying to understand your steps, are they in sequential order? The 3rd step. You say you decarb the oil. You mean you reheat it after all visible bubbles disappear?

            Do you vacuum purge or are you speaking about purging the BHO with ethanol by allowing the bubbles to escape, in step 2? Or are you reheating your oil prior to vacuum purging, then adding ethanol?

            Is a thin film vacuum purge different than purging with a chamber a hose a valve and a dual stage pump?

            Thank you again for your time! You have shed much light. I just want our oil to taste right.

          • No, we add the ethanol, winterize, remove the alcohol, and then decarboxylate the oil.

            We decarboxylate oil by placing a container of it in a 250F hot Canola oil bath, and watch the bubbles. See our procedure at

            We don’t bother to vacuum purge oil that we are decarboxylating for oral use. We use vacuum to keep the heat low so as to preserve carboxylic acid for vaporization.

            A thin film purge is vacuum purging the material spread out in a thin film, so that the solvent can more readily escape.

          • Posted by funkmecca on April 5, 2013 at 1:00 PM

            Thank you again for clarification and link! I appreciate your time and lend of knowledge. It is very generous and well informed.

            For the oral BHO, you do the steps regarding carboxylation and the hot alcohol.

            For vaporization what you guys will do is just the extraction onto surface area of choice and then use the thin film technique to extract the leftover gases or butane trapped inside the BHO? At low heat to preserve the carboxylic acid at about 115 F, while vacuum purging? Sorry, if this is mundane and obvious. Obvious newbie here.

            However, I am curious. Can you vaporize the oral BHO?

            Also, would like to know if there is anything I should know as far as steps and advice for making BHO for vaporization?

            Thank you kind sir. I appreciate all your help in advance.

          • Yes, we always decarboxylate our oral meds and remove the inert waxes.

            Yes you can vaporize oral decarboxylated BHO, but usually don’t with our oral formulas, because of the other things that we add like cinnamon and myrrh.

            The other difference between the decarboxylated AA that we produce for oral and topical use, and the Carboxylic acid AA that we produce strictly for vaporization, is that one is in the decarboxylated nonpolar form, while the latter is still in the original polar carboxylic acid shatter form it was in on the plant.

            Both work for vaporization, but the THC will typically be slightly higher with the carboxylic acid shatter form, because less of it will have been converted to CBN.

            We get bragging rights vaporization shatter by putting about 3/16 to 1/4″ in a shallow dish and heating it to 115F in a -29.9″ Hg vacuum. Control the pressure until all violent boiling stops and then allow to cook under vacuum until the random sized solvent bubbles are gone, but remove as soon as only the fizzy equally sized CO2 and terpene bubbles remain. Remove it from the chamber at that point and let cool.

          • Posted by CALumi on April 8, 2013 at 5:01 PM

            Well, the proof is in the pudding. I followed your steps. Using the thin film technique. One question I have. The initial purge was on extreme low heat. All major bubbles dissipated during this time, like you said. It was 2 hours of vac purging. Finally I took it out and let cool down. I tasted a slight dab. The taste was 10x better than when I did it the last time as a result, it gave me that resin taste in the back of the mouth that I got from the very first dab I ever had. I used an older batch of material, but all flowers. I extracted onto a glass dish that sat in warm tap water. The thin film technique was used and I got shatter. The constancy was hard like candy. I thought it needed more purging so I did an additional purge using slightly higher temperature than the last time (never above 101 F). I got more of a raw honey consistency and the taste is a little modified. Now, it is easier to handle with the glass dabber. It vaporizes rather quickly and the taste seems to be more acidic? Not in a bad way at all.. It seems to taste that initial taste and then it turns into a bite at the end. Is this based on preference at this point? I can do it how I did it the first time, by allowing it to sit on a warm surface no higher than 90 F and I can get shatter. The taste is amazing either way, but do you think I lost something when I did it the second time because the consistency changed and so did the taste. I noticed it had less bubbles in between time and they seemed to appear smaller and denser. I am just wondering if there is one better for you than the other? The raw honey one seems to have a sheen to it in some parts, is this ok? Do I need to do an additional low heat and purge? The parts that are like raw honey, change color when I move it with the glass dabber. Is this a good sign? Which is better? I probably did not need the second purge, but it is much more easier to dab with. However, I think the taste of the shatter seems cleaner and crisper than that of the second purge. Your feedback would be greatly received. Thank you GF for all your help. I appreciate everything!

          • Sounds like you are trying all the right things!

            I get consistent shatter at 115F under -29.9″ Hg vacuum. I purge until the random sizes solvent bubbles cease, and only the equally sized fizzy CO2 bubbles remain. I then pull it and let it cool.

            The honey consistency is because of decarboxylation and will have a lower terpene content and be less floral, as well as have slightly lower THC and higher CBN. It is still good and we routinely vaporize both.

          • Posted by CALumi on April 9, 2013 at 3:05 PM

            Dear GW, I attest that you have shed much light to my myopic ways of thought and have helped me think differently. Your forums helped to simplify how I was making BHO by using your thin film technique ..I really did not realize how much heat plays a role in making your BHO taste delicious. I was taught to let all bubbles disappear. Now, I know from proof that this is NOT TRUE. My last batch was amazing in taste, smell and consistency. I messed around with temperatures and found that less is better using the thin film technique. A few questions that I have and I do not know if anyone has ever asked? What should I do with all my BHO reclaim that is not as good as what I am getting now? I have some stuff that is reclaimed via ethanol and some that I basically purged at too high-heat, resulting in the taste to go away, but the potency is there. Should I throw-out the old reclaimed wax? Or can it be recycled maybe for an oral recipe? Green elixir? Something of the sort? Also, what do I do with the left over extracted material? Some of it smells really fresh still. Could I make a QWET extraction from blasted material?

            Thank you in advance.

          • We make an sedative oral or a topical with our reclaimed oil.
            I would repack the tube and run the material again if microscopic examination showed that there were still trichome heads left. You could also make a QWET.

      • Posted by Zephyr on May 14, 2013 at 4:36 PM

        When you say Whattmann “#1″ are you referring to Grade 1: 11 µm?

  126. Posted by fullmeltmike on March 28, 2013 at 7:06 PM

    Is there a method for using kief only with the column?

    • Yeah, we’ve used a 6″ column on a Mk III for extracting kif with good success. We haven’t tried longer columns, over concern for plugging.

    • Posted by Sppete13 on April 1, 2013 at 7:47 AM

      I love Skunk pharms Butane Thermos QW method with kief…. just make sure you put your butane in the already cold thermos BEFORE putting in your kief…. or it can get messy :-)

  127. Posted by Mookie on March 26, 2013 at 2:05 AM

    You guys are hella cool and about the mission. Many blessings.

  128. Posted by M C on March 16, 2013 at 11:45 AM

    Also, my resin puddle is maybe an 1/8″ thick, will this still purge in vac tank?

    • Yes, if you heat it to about 115F.

      • I have 2 questions. first one, if my oil comes out dark, like dark brown or even black is there a way to remove that color and make it more clear? yellow? Obviously the better looking product i use doesnt come out that color but i was just wondering. and my second question is how to get HARD SHATTER SNAP at room temp every single time?? Sometimes it glasses up in like no time at all and when i take it out its perfect. other times ive left it in the vac and literally gone to bed, woken uop the next morning to take it out and it was STILL sticky! WHY? help please.

        • The dark color is usually a function of heat and age of the material. Young fresh material is lighter colored than older dried material, because the carboxylic acid forms are lighter in color than the decarboxylated forms. Consider the trichome that matures from clear to dark amber………….

          Sativa oil is typically lighter than Indica’s.

          Removing it is not easy and the only reliable way that we’ve found so far, is using ionic resin columns, which is slow and expensive. In most cases, it is easier to not darken the material in the first place.

          Shatter is carboxylic acid. Any decarboxylation makes it softer and more maleable. We get it most consistently by using young material and using thin film purging at 115F and -29.9″ Hg.

  129. Posted by M C on March 16, 2013 at 11:32 AM

    Hey, back again!
    OK, tearing my hair out now. I had gotten a process down to deliver a very nice extract in a flake form. Growers came out of the woodwork to dump trim on me, now I can’t get clean extract, everything tastes contaminated, never seems to stop bubbling after 10 hours under vacuum. After finding another online info resource on Utube, I tried a colder (120 deg f) longer purge. 20 hours at about 120, I have burned oil with butane or something in it. I had been using power 5x, but given a deal on Dodo 7x I switched. I also went from an entire steel canister as vac chamber, to a stainless lid clamped onto a pyrex bowl so I can see inside. I also have a cheapo harbor freight vac pump.
    I am out of money, barely keeping power on, sitting on loads of material that is getting older, with folks calling me. And I cannot get my product made to save my life. Which is what I need it to do before I lose my house. No more money to pour into gear.. I am stumped. I am at 29 in merc vac according to guage. ?? help. please.
    M C

    • Were you flaking shatter, or were you making wax?

      The oil will continue to bubble after the solvent is all gone, from decarboxylation.

      We use 115F and -29.9 to produce shatter in thin films in a couple of hours. We watch it closely, and when the random sized bubbles stop and only the small equally sized fizzy bubbles are left, we remove it from the chamber and let it cool in the open air.

      If you are making wax, some strains wax up easier than others. 125F at -29.9″ for as many hours as it takes, usually 10 to 20, should get you wax with the strains that we typically work with.

    • Posted by chives greenthumb on March 26, 2013 at 10:58 PM

      make sure the product is not stale or full of fan leaves. Both of these will cause that taste you are mentioning and make set up much harder.

      • Good point! Fanleaves work well for pain, but they don’t taste very good and give you a charlie horse between the ears instead of euphoric head effect. Ostensibly because of the older more mature trichomes, which are sedative.

  130. [...] Check out Jumps Absolute Amber thread for details or the last procedure detailed on the page at Reply With [...]

  131. [...] by mokuro if possible, what is Double solvent method? can you link me some tutorial about it? this guys the shit! Check out YouTube as well. Type in winterizing BHO. Reply With [...]

  132. Posted by aaron on February 23, 2013 at 10:08 PM

    hey ya’ll wondering if someone can answer something for me. i bought my bho steamroller from a guy who said i could reclaim my bho resin using some process of rubbing alcohol, then letting it vapor out over a weeks time, then you can resmoke your lost dabs… has anyone heard of this? and how exactly is it done?

    • We clean our oil rigs in ethanol, by emersing them in alcohol until the resin is dissolved in it. You can speed it up by heating the alcohol.

      We make a sedative evening med out of it, by cooking off most of the alcohol in our still, and boiling the rest off to atmoshpere, with the oil container sitting in a 250F hot Canola oil bath. When it stops bubbling, it is ready.

      • Posted by aaron on February 24, 2013 at 10:51 PM

        Would I get the same results from using 91% isopropyl? Sorry Im sort of new at this whole thing. Initially I was concerned about heating it too, thought maybe it might kill the potency? Also, what kind of container are we talking for the aforementioned ‘oil container’. Is this beyond my ability to do at home on the stove? Thanks for the information

        • Not sure exactly which oil container of which you speak, but we usually use stainless bain marie wear from the local restaurant supply to hold the oil and set it in hot Canola oil in an electric fondue pot.

      • Posted by john on February 27, 2013 at 1:15 AM

        How much canola oil per / g of absolute ethanol ? You guys are the best

        • Umm, could you elaborate on the question?

          • Posted by John on February 28, 2013 at 9:53 AM

            Yes, I have about 2 grams of absolute extract that I got from reclaiming my piece with everclear numerous times before winterizing and pouring through a coffee filter onto Pyrex on top of a pot of water on its lowest setting, Let it sit for about 5 hours .. Now what? I usually just hit it on a nail again but I really want to try this canola oil and didn’t know how much to use. Thanks!

          • If you are mixing it with Canola oil to make an oral, it will mix at any ratio. 100 mg is about the standard dose for a low tolerance person, so if it is mixed 50/50, you would have to take 200 mg to get a 100 mg dose.

            For oral, we generally add about 33% coconut oil, but as long as you do the math, you can pick our own ratios.

          • Posted by john on February 28, 2013 at 11:46 AM

            Thanks! Can’t wait to try it! As for my ethanol reclaim process, anything I should tweak or change?

          • Sorry John, can you elaborate on your question?

      • Posted by frank l jones on June 9, 2013 at 12:49 PM

        been wanting to ask about the reclaim still ,im about to order the parts to
        build a unit once again I do thank you
        so is this unit suitable for small bathes? like im only doing small batches.
        in between harvest like only a coulpe of ozs each time once I feel like Ive got this dialed in then I plan on running like half pounds,so is this unit overkill?
        or would I be better off using a distiller set up?how long would it take to reclaim 1/2 liter? just to get a idea

        looking forword to hearing back

  133. Posted by steve on February 23, 2013 at 3:04 PM

    First BHO run today and i have a question. When you smoke concentrates, are you supposed to get a film, residue like feeling inside your mouth? or is that butane? smh

    • That is most likely plant waxes that are present in a raw oleoresin or concrete. We remove those waxes by winterization, if we are going to use the oil for vaporization.

      We also remove it for oral meds, because they are basically inert and dilute the potency. We remove it from our topical, because it is left behind on the skin and prills up when rubbin the topical in.

      Removing them also removes some of the lighter terpenes, so the flavor loses some of its flora undertones.

  134. Posted by James on February 20, 2013 at 2:32 PM

    Was also wondering how many minutes you guys purge absolutes at ambient temperature in the 6″ petri dish (3/16″ of resin). Please let me know if there is a more appropriate forum to discuss this in. Thank you!

  135. Posted by James on February 20, 2013 at 2:20 PM

    My vacuum chamber reads at almost 28″Hg, more like 27 3/4. Is this enough negative pressure to evaporate ethanol at ambient temperatures? If I applied heat from the bottom, what temperature would you recommend? My chamber is made of thick stainless steel.

    • That could be either your gauge calibration, leakage, or that may be the relative pressure at your altitude. Did you calibrate your gauges zero, hot tight is the system, and what altitude are you at?

      Some gauges faces twist off, and there is a calibration screw in the face near the bottom where the sweep hand pivots. Vacuum grease can help seal mating surfaces, and if 28″ Hg of absolute pressure is all that you have at your altitude, it is the same as -29-9″ Hg.

  136. Posted by Ben on February 17, 2013 at 7:00 PM

    Hey GreyWolf, i was wondering your opinion on soxhlet extraction, like the Eden labs Coldfinger?? What solvents what be best, if any??

  137. Posted by nugget1 on February 17, 2013 at 10:33 AM

    i have made a batch of oil and i hot water bathed it then put it on a skillet at which bounced between 125-140 it sat for an hour i poped the bubbles with a pin then at about an hour and half when i went to pop the bubbles it buddered up. I put some on a pin and put a torch to it and it crackled quite a bit is there any way to re purge to get any remaining butane out?

    • You can continue to purge until you feel it has achieved your desired consistency. You may be dealing with residule water not butane. Butane would just burn. Water will evaporate if left at 140F long enough. I would suggest a quick trip north of 212F to make sure its gone.


  138. Posted by James on February 12, 2013 at 1:18 PM

    Before I go ahead and purchase these tubes, I was wondering if you could forsee any problems using poplypropylene pipe 36″ length and an inch in diameter. I know the chemical comparability is fine, but do you think I would need some kind of gasket between the male threaded pipe and female end cap? Just not sure if the PP threads would be air-tight.

  139. Posted by James on February 11, 2013 at 9:50 AM

    Great news! Thank you for the fast reply.

  140. Posted by James on February 10, 2013 at 7:38 PM

    Was curious if you guys knew what PSI would be in a flowing packed column 36″ in length and 1″ in diameter. I’m looking into using schedule 8 polypropylene pipe with an end cap on one end and clamped filters on the other. The max rating for these tubes is 250 PSI, hopefully this is safe. Thanks for any and all help. Hope to see you in March!

  141. Posted by Dr teeth on February 10, 2013 at 11:46 AM


    I recently purchased 170 proof ethanol (the best I could get in Ca) and did a small test run. I was not very successful and had a very difficult time purging the water out.

    I’m wondering if 99% isopropyl alcohol is acceptable for absolute amber production?

    On a side note, acrylic reacts with alcohol by cracking. So be careful with what you make your purge chamber out of. Mine imploded and it sounded like a shotgun. I was very fortunate to not be staring at it at the moment.

  142. Excuse the post if in the wrong area, but what are your thoughts on this product in use for cannabis alchemy? Is it safe for use? Ultra-Ever Dry is a superhydrophobic (water) and oleophobic (hydrocarbons) coating that will completely repel almost any liquid. Ultra-Ever Dry uses proprietary nanotechnology to coat an object and create a barrier of air on its surface. This barrier repels water, oil and other liquids unlike any coating seen before. The other breakthrough associated with Ultra-Ever Dry is the superior coating adherence and abrasion resistance allowing it to be used in all kinds of applications where durability is required.” video here…. Thank you for all the information, have a great day!!!

  143. Posted by M C "Mr. Science" on February 6, 2013 at 3:33 PM

    Hello good people of the S-P,
    I never made it down to visit in person, as my life is, .. , vigorously evolving. But rest assured, I have been very busy in the Z-L (zombieland) refining my extraction technique, apparently to a look that is unseen around here. One of the vendors I process for has asked me to just make the sticky shatter because people know what it is and he can’t / is tired of explaining what this stuff is.
    I started calling it “Absolute Sugar” tm.
    So, after having the rest of the internet give me enough info to get people sick and maybe blow myself up, I joyously found this (and many more) thread and had the process come together.
    The material:
    I have used everything from big honking yellow leaves mixed with sticks and crumbles to tiny flavor samples of AAA flowers. I think the most important aspect of the material is uniformity. It can be really dry or a little moist ( and I mean little) and it can be material from any where but the stem I suppose, but it should be uniform in size and moisture content. If uniformity is not achieved, partial extractions as well as leaching undesirable elements out faster than normal occur. I work with glass as well, so I have the benefit of having a kiln that is usually somewhere between 400-1000 deg sitting around that I can lay material out near to dry it if need be. I then put on a leather glove and push/grind all the material through a #10 screen. The material is ready for packing the
    Glass Column:
    I am using medium wall tubes with an ID of 1″ various lengths, the average holds about 40 grams. The glass has a dome and orifice on one end and the tube is flared on the other, assisting in keeping screens on.
    Collection vessel:
    I run the butane through and into a shallow wide pyrex bowl. This sits in oil (cooking) in a binks pressure pot (used for painting) with rubber gasket, ports, etc, but no view window. I am using carbon steel now, but as the product never comes in contact with it, and has a lid on during purge (overhead drips from lid). This sits on a hot plate in front of a large explosion proof fan in my shop. The fan is run by a pulley to a remote motor isolated from the work environs.
    Heat the collection tank to about 200 and start running either 5x or 7x butane through the column. After a while of watching the flow of butane, having run many many columns, I started to release pressure from the can valve, but keep the orifice covered, stalling the butane for a little soak. I usually run 2 cans through (300 ml ea) and had been running them back to back. I noticed after an experiment however that more extract can be gained by being able to “wet” the material more times. The brunt of the solvent kick is when it initially wets the material, it seems to me. So I took a column, and took note of the color of the eluate. Then I took the same size column packed with the same material, ran one can, used compressed air to blow it out thoroughly, then ran another. The initial eluate was almost as amber as the eluate from the beginning of the first can. It ran to clear much faster than the first can of course, but it seemed obvious that a gain was made.
    Next I thought about very pollen heavy material and the possibility of “mud” blockage, or getting a puck formed in the tube that the solvent then takes path of least resistance and does not work on. What about back flushing? The next trial was releasing the bottle slightly from the orifice to allow some butane to escape, enough so I see material move up the column a little, then press the bottle back to correct flow. Hard to gauge if this is really helpful without a bit more precise testing and measuring.
    OK, pot of very cold amber bubbly butane purging off until it is a thick fluid with more occasional bubbles, raise heat to 160 deg f. and vacuum down to -29 for a while. I have to open and check temp a few times to check the temp and make sure I don’t burn it due to the lack of precision in my equipment. Once it is flat, it is fully purged. Different strains seem to take different times.
    Now I put the product back into solution in either ethanol or methanol, freeze for many hours depending on schedule, then strain through coffee filter. Marvel at the odd mud left, of course I have gloves so I can gently squeeze out the filter to get the most product.
    Then it gets laid out on glass sheets, I tip them back and forth to thin the material and let it cure in a warm area for 7 hours or so. Then I quickly cool it, usually by just setting outside in Seattle. When it is cold, I feel check the product, especially the thick spots to make sure it is hardened, not sticky or mushy. Then I razor it up/flake it off the glass. I use parchment over the scraper due to the stuff popping 2-3 feet away sometimes when scraped. What I have is a pile of amber crystal flake stuff that generally does not melt back into an amber shard if kept cool. Not freezer cold, like in a cabinet so warm temp spikes in the room don’t bother it.
    Some people like this as the final, some want shatter. I weigh it up into grams then flash it on parchment in front of the kiln. The stone is usually over 190 deg, but the pile of sugar is not there long enough to get over 125 deg. Just watch it, when flat, cool, break into chunks for packing. Very transparent. One vendor made a joke about do I have one with a thousand year old fly in it.
    I have pictures of all this stuff if you want to see. I have put off writing this as I knew it would take a while.
    Just today I had a client say the last stuff popped on the nail when he went to vaporize it. This generally means butane. It was a small batch, so not a bunch of people got some, but no one else has complained, and I certainly have not had any pop when I vaporized it.
    The only difference in the batch was I went to plastic containers at the urging of a vendor instead of parchment envelopes. I measured out the grams into the cups, put them on the warm stone, watched the sugar melt down in a few seconds and removed to cool.
    I did have one cup left over short a gram, with sugar not melted. I vaporized, no pop. I put the cup in front of the kiln, and when it melted down, bubbles started to appear. I removed it, cooled a little but not to full harden, vaporized, no pop. I did not inhale to taste, nor did the client.
    How can there be butane after the methanol wash and cure??
    All other batches before this pineapple express have been fine with repeat clients.

  144. Posted by Budhappy on February 4, 2013 at 12:21 PM

    One other thing, the thermos soak was for about 1 hrs each time, and got maybe 20 hits each time. Even for the fresh ph that was done today.

  145. Posted by Budhappy on February 4, 2013 at 12:19 PM

    Hi all.

    Just wanted to say that I ordered a vacumn chamber and had my first vacumn purged bho oil. I don’t think that I would ever smoke any other kind. I picked some buds from my purple haze, super lemon haze, and cheese, and a homemade hybrid of of slh x “oracle”. These are still a few weeks away. Haven’t started flush yet. First picked fresh buds, then stuffed them in large honey bee extractor.
    -30C here, so placed outside for 12 hrs. Blasted 2 cans of near zero impurities butane. Not much oil at all. 15-20 good tokes maybe.. Ended up being the color of hard honey. Not really yellow, more clear. Dabbed it with a buddy, (going to buy one of those too, a dabber tastes awesome), and wow. This doesn’t taste like oil. It’s like walking into a flower shop, and smelling with your taste buds.I could feel the residue all over my teeth, gums, cheeks for about 15-20 mins later. Very uplifting and gave me goosebumps after about 25-30 secs of inhaling. I rewashed the weed in the thermos method, and it came out really yellow. No heat was needed for the purge, room temp and oil was still pliable. The rewash tasted about the same, but not quite as potent. The comedown made me a little tired. Just thermosed some purple haze today and came out dark yellow as well. I have been a smoker since ’84, and never tasted oil this good. Just my 420 cents worth.
    Happy medicating!

  146. [...] not so little write up , covers a lot of shit. more than I even read. now let's make some more oil! Colorado Amendment 20 compliant! I gave up playing guitar to grow weed, I gave up tv to [...]

  147. Posted by star crash on February 1, 2013 at 8:47 PM

    So , instead of a thermos , I tried a one quart mason jar as a collection vessel . Experimented with 20 g’s of popcorn bud and soaked them for one hour (outside temps are below freezing so this was easy) that filtered that liquid into a tray , let the solvent (butane) evaporate , re-dissolved in 191 proof ever clear & let evaporate again

    Yield was .75 g’s of very clear amber.

    2′ND wash the buds were powdered and soaked in the mason jar for 2 hours & again follow the above steps

    Yield was 1.25 g’s of a darker , yet still translucent “amber grade” extract

    so , around a 10% total return in an extremely easy fashion . Total butane used was 1200 milliliters

    how I’d do?

    • Good job, your 10% yield is in the ballpark for popcorn, so it sounds like you probably got it all and very clear amber, plus your darker amber grade sounds like the right colors.

      The real test is in the taste and effects! After trying it, how do you think it turned out?

      • Posted by star crash on February 4, 2013 at 9:55 AM

        Taste is exquiste It’s incredible!! I vaporize with a dome globe & titanium nail set up. One small dose & I’m thoroughly medicated in a way that smoking cannabis flowers just can not achieve. These extracts are a true “shatter amber” and I can’t really call it an “oil” per say . I’m very proud . I’ve been smoking cannabis since 1973 & at almost 52 years of age I’ve really discovered something special , thanks in part to folks such as yourself. I will try to get some pics up at icmag…

        much peace from Star Crash!

  148. I found desecration jars at amazon I also have a vid on making a great chamber out of a co2 alum pressure vessel the des jar is good to 29 inches of mercury complete and total evacuation at EXTREAMLY low temps

  149. Posted by Thai Sam on January 23, 2013 at 5:44 PM

    Candy topical cream cough drops chapstick and questionable to some animal treat slash meds

  150. Posted by Thai Sam on January 23, 2013 at 5:37 PM

    decarboxylated oil plus your favorite honey plus 2 teaspoons of coconut oil plus proper catalyst and mixing procedure makes absolute 100 percent measurable amount gof THC given proper storage measures. that can go into any recipe, homemade soda, favorite drink

  151. Posted by Thai Sam on January 23, 2013 at 5:17 PM

    Allows larger quantities of oil to come out cleaner with less effort for medical use via vaporization and seems to leave the high in cannabinoid leaf material or cellulose to be extracted for topical use. I would like to know if I’m losing out on precious Micro chemicals in my head stash by using this mmethod

  152. Posted by Thai Sam on January 23, 2013 at 5:10 PM

    silk screen from bubble bags work very well for screens and a add a question for anyone.
    does oil made from only kief only have a different chemical composition then usin g kief and plant material or celluose together at the same time. I find that in all kief g extraction allows larger quantities of oil additional in vaporizer a shin use to be extracted

  153. Posted by jesse on January 20, 2013 at 6:14 AM

    According to the cole-parmer compatibility chart butane causes a severe reaction to silicone, so what are you suppose to vac purge on after you scrape it off Pyrex? I saw you say it was ok to blast onto parchment, although certain company started producing ptfe paper specifically for that purpose. Thoughts? Another question I have is I scored a vac oven on ebay for 100 bucks but it doesn’t a window in the door so I have to open it to check on the oil, is that problematic? Can I replace the door with lexan or will the butane cloud and crack it? Also you guys rock and I wish I could come to or to take a class but I live in ri

    • The word Silicone covers a range of manmade polymers, based on a silica backbone, with carbon, hydrogen, oxygen, and other atoms bonded at the atomic level. It is used in oil and grease, silicone rubber, silicone resins, silicone caulking, adhesives, etc.

      We may be talking semantics and word usage with the Cole-Palmer compatibility charts, as they are soaking mostly gasket materials in different solutions, to observe weight gain, loss, and change of physical appearance.

      The polymers don’t all react the same to n-butane, and another issue Cole Palmer would have against using a silicone gasket material, is its gas permeability. It is about 400 times more permeable than butyl rubber, so while it is super for medical applications requiring aeration, it stinks for a gas tight seal.

      A silicone resin spray, doesn’t care about gas permeability, and the n-Butane molecule has full valence orbit, it is not likely to react with the highly inert Silicone resin. Neither appears to be reactive enough to start or support a reaction at the temperatures involved.

      I would be more concerned about PTFE finding its way into my heated oil, because even though it has a combustion temperature that starts decomposing it as low as 200C/392F (163C/325F?), if you read the fine print of the following two links, you will note the following issues, amongst them HF acid as a pyrolysis byproduct:

      Acute inhalation toxicity: The thermal decomposition vapours of fluorinated polymers may cause polymer fume fever with flu-like symptoms in humans, especially when smoking contaminated tobacco.

      The pyrolysis of PTFE is detectable at 200 °C (392 °F), and it evolves several fluorocarbon gases[21] and a sublimate. An animal study conducted in 1955 concluded that it is unlikely that these products would be generated in amounts significant to health at temperatures below 250 °C (482 °F).[22] More recently, however, a study documented birds having been killed by these decomposition products at202 °C (396 °F), with unconfirmed reports of bird deaths as a result of non-stick cookware heated to as little as 163 °C (325 °F).[21][23]
      While PTFE is stable and nontoxic, it begins to deteriorate after the temperature of cookware reaches about 533 K (260 °C; 500 °F), and decomposes above 623 K (350 °C; 662 °F).[24] These degradation by-products can be lethal to birds, and can cause flu-like symptoms in humans.[24] In May, 2003, the environmental research and advocacy organization Environmental Working Group filed a 14-page brief with the U.S. Consumer Product Safety Commission petitioning for a rule requiring that cookware and heated appliances bearing non-stick coatings carry a label warning of hazards to people and to birds.[25]
      Meat is usually fried between 400 and 450 °F (204 and 232 °C), and most oils will start to smoke before a temperature of 500 °F (260 °C)is reached, but there are at least two cooking oils (refined safflower oil and avocado oil) that have a higher smoke point than 500 °F(260 °C). Empty cookware can also exceed this temperature upon heating.
      Perfluorooctanoic acid (PFOA or C8) has been linked to cancer, thyroid disease, ulcerative colitis, and high cholesterol.[26] In the form of an ammonium salt,[27] it is used as a surfactant in the emulsion polymerization of PTFE,[28] [29] and has been detected in some PTFE products. [30][31] The levels that have been measured in nonstick cookware range from not detectable to 75 parts per billion.[31] [32] These are lower than in PTFE products such as thread sealant tape (with 1800 parts per billion (1.8 parts per million) of PFOA detected) because nonstick cookware is heated to volatilize PFOA.[30]
      A DuPont study on Teflon PTFE did not detect any PFOA above their detection limit of 9 parts per billion,[33] and DuPont says no PFOA is in Teflon brand cookware.[34] A 2009 USEPA study found levels of PFOA in nonstick cookware ranging from undetected (with a detection limit of 1.5 parts per billion) to 4.3 parts per billion.[31] DuPont says there should be no measurable amount on a finished pan provided it has been properly cured.[35] While PFOA has been detected in the low parts per billion range in the blood of people,[36]exposure from nonstick cookware is considered insignificant[37][38] —despite the marketing of other wares. However, at temperatures well above those encountered in cooking,[39] PTFE pyrolysis can form minor amounts of PFOA.[40][41]
      In January 2006, DuPont, the only company that manufactures PFOA in the US, agreed to eliminate releases of the chemical from its manufacturing plants by 2015,[42] but did not commit to completely phasing out its use of the chemical. In the emulsion polymerization of PTFE, 3M subsidiary Dyneon has developed a replacement emulsifier[43] despite DuPont stating that PFOA is an “essential processing aid”.[44] As of August 2008, the EPA’s position was that it “has no information that routine use of household or other products using fluoropolymers, such as nonstick cookware or all weather clothing, poses a concern.”[45]


      • Posted by jesse on January 21, 2013 at 9:24 AM

        Thank you. So do you think it is worth it for me to make a transparent door for my vacuum oven?

        • Yes, but probably not out of Lexan. In the right thickness it would be strong enough, but wouldn’t like any upper 292F decarboxylation temperatures and might suffer high cyclic fatigue.

          Lighting the oven and installing a tempered glass sight glass, or small glass window just big enough to tell what was going on might work better. For design purposes, glass has about the same rigidity as alumnimum. Both have “I” values of 10 X 10-6, while steel is 30 X 10-6.

          • Posted by Dr teeth on January 21, 2013 at 10:57 AM

            I justed used 3/8″ acrylic for my homemade vacuum chamber. I cycle it often and for long periods and it has no problems. My 14″x14″ piece cost me around $25. It rests on top of a 20 quart aluminum pot that was $38 shipped to my door. With my vac gauge, brass fitting and vacuum hose my entire 5 gallon (12″ id) vac chamber was under $100. I suggest people just go look at some diys instead of giving the DIY guys on eBay around $120 profit.

          • Good show building your own! How hot have you operated it?

          • Posted by jesse on January 22, 2013 at 5:39 AM

            Yeah making my own was next if the vac oven was broke, I feel safer running an oven for ten hours, saw too many crushed stock pots on tc lol

          • Yeah, it definitely requires a heavy wall pot, as atmospheric pressure is almost 15 pounds per square inch.

  154. Where did you source your information that our sensory threshold for n-butane is 6.61ppm? thank you. A link would be greatly appreciated!

    • Hi FE! Sorry, after four hours of searching, I haven’t located my original source, so I’ve changed that reference in the posting. Thanks for pointing it out to

      As I recall, it came up in a search on the suitability of n-butane as a food propellant, but too much time since I researched it too few brain cells left. If I run across it again, I will record the source and give you a heads up.


    • Posted by Mark on January 23, 2013 at 9:17 AM

      Hello Skunk Pharm Researchers. Thank you for all of your dedicated work here. In reference to a question posted by fobextractions, Jan 18, 2013, I have found a different value and source for the sensory threshold of n-butane. The TEXAS COMMISSION ON ENVIRONMENTAL QUALITY published “FACT SHEET Butane, All Isomers” July, 2012. The bottom pf page 1 states, “An odor detection threshold of 1,200 ppm was reported for n-butane.”
      Hope this helps!

  155. Posted by Dr. Teeth on January 9, 2013 at 2:51 PM

    Sorry, I have a lot of questions. I’m a strong believer in “The waiting man gets the wind behind him. So stop rushing into things and plan properly in order to be successful”.

    1) What length for single pass extraction do you recommend? Also with a 1″ diameter, how much dry material can you fit into… say a 2′ long extraction vessel?

    2) I am wondering what vacuum pump and purge container you are using and if you can link where I could purchase one or one similar online? I noticed that your purge container has a rubber stopper that can allow the power cord for your hotplate to work. Would you still recommend using a hotplate or could you simply submerge the purge container into temperature controlled hot water?

    3) I had a friend point out to me that a metal extraction vessel has a possibility of creating a spark and starting a fire; so he recommended using plastic. Do you find these claims to be valid or not really worth worrying about? I can order PP online or get SS locally, they cost about the same.

    4) As for the filter at the end of the extraction vessel, is a certain micron recommended or does any fine mesh work?

    I’m sure I have more questions but cannot think of anymore at the moment.

    Thank you

    • When using columns, I ended up with three glass ones. A 12″, a 24″, and a 36″. By a factor of 10X, my most used one was the 36″ and the least used the 24″. I either had a short run, or was in a hurry with a long one.

      How much weight you get in a column, depends on what it is and how hard you pack it. For instance, a 1 X 1 1/2″ X 24″ column on a Mk IIIA has 35.6 cubic inch internal capacity, and holds from 135 to 203 grams of material, depending on whether it is prime bud or trim, how wet it is, and who is packing it.

      The way we prepare our bud, I pack about 150 grams in that column, so that is about 4.2 grams per cubic inch. A 1″ X 24″ column would therefore hold about 80 grams.
      Our pumps range from a surplus MASH pump, a CPS VP6D AC vacuum pump, and a Robinair 15500. We got them all off e-Bay.

      I picked up a glass vacuum desiccator from American Scientific, but you might look at what they use in the epoxy casing industry to degas castings.

      You can simply submerge a suitable container in hot water and in fact, we also do that using a Lil Terp tank.

      Your friends concerns are ill founded and the Terpenator won’t work in plastic, because of the heat transfer rates. The butane is in a closed cycle, where there is no oxygen to burn, nor any way for a spark to get to it, unless you have a leak.

      Because it always possible to have a leak, we use these puppies only in well ventilated areas, and away from ignition sources.
      As the joke goes, “Please lean back and relax for your trip, as all human error has been removed from the controls of this vessel and absolutely nothing can go wrong, go wrong, go wrong, go wrong………………………………..

      We use a 20 mesh screen at both ends of the column, and pack two wadded up coffee filters in both ends of the plant material, which the screens hold in place.
      We also filter it with a coffee filter, when we wash it out of the container with ethanol, and again after we winterize the ethanol to remove waxes. We use either a coffee filter, or a #1 Wattman (17mic) filter, with a vacuum assist.

      If we are serious, we then filter with a 0.2 micron syringe filter, to get out mold and bacteria.

  156. Posted by Les Reasonover on January 7, 2013 at 3:46 PM

    What is the benefit, if any, of ingesting oil with THCA (low heat purged Concrete) as opposed to oil that has undergone decarboxylation with THCA converted to THC? I have found ingesting oil that has not undergone decarboxylation, that contains high THCA and low THC provides good pain relief with less intoxication.effects. Is this the reason for making such a oil? If not, what are the reasons? Are there some conditions the high THCA and low THC extract is more effective for?
    Great info! Thanks!

    • I am asking those same questions, as it would appear that undecarboxylated cannabis oils still cure things. Is decarboxylation only necessary to make the THC pass the blood brain barrier more readily, so that it is orally active?

      So far the best answer that I have is that THCA may act on other receptor sites than the CB-1, to create its effects.

      • Posted by Les on January 9, 2013 at 1:44 PM

        …or reacts to the CB-1 receptors in a different way… or decarboxylates in the body releasing over time? I seem to get some psychoactive effects from undecarboxylate oil/bud. Is this THCA or CDB or some combination thereof or is it a small amount THCA that has been decarboxylated? Either way, I’m thinking it is essentially the same as ingesting fresh bud (a very nice and popular way to medicate, for pain at least) without the hassle of a constant supply of ripe fresh harvested material. Thanks for your input!

        • The CB-1 receptors are in the brain, so the blood brain barrier issue would be a problem for polar carboxylic acid.

          CBD, reacting mostly with the CB-2 receptors scattered throughout our bodies, doesn’t produce psychoactive results, as it is an analgesic. The CB-2 receptors do however control much of our immune system, so I’m guessing it is the CBD that is responsible for much of the effects and it doesn’t have to be decarboxylated to reach the CB-2 receptors.

          • Posted by Dayzt on January 10, 2013 at 9:00 AM

            Great conversation regarding CBD! I just wanted to add… decarbed or not, infusing it with something (ie: cococnut oil) will help keep it ‘tied up’ in your system longer, thereby giving a better chance to be effective before it passes through the body. Just my 2c =)

          • Very good point! One of the purposes of coconut oil in our orals, are to tie up the liver processing it, so as to increase cannabinoid residence time.

          • Posted by Les on January 11, 2013 at 7:47 AM

            Yes Dayzt, I have been using olive and grape seed oils for ingestion but after reading here I see there is evidently an advantage to using coconut oil. I rub a couple of drops of ~1:1 BHO and carrier oil on my gums. Works fast and great! Thanks again for the excellent info SPR. Very helpful!

          • Ohmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm!!!!!!!!!!!!!1

          • Posted by CannaBliss Liberty on February 23, 2013 at 4:58 PM

            Just wanted to point out that CB1 receptors are also expressed in liver, fat, muscles (there’s more) cells, digestive tract and in the lungs and kidney’s, to name a few. There is also large concentrations in the spine.
            Also Dr. Courtney has said that there is some evidence that show the so called “CB3″ receptor (which does not respond to any active Cannabinoid) responds to Cannabinoid Acids.

  157. Posted by hitboro on January 7, 2013 at 11:46 AM

    Hi! Could you please help me come up with a way to filter the sulphur out of my shatter? It’s the best looking extraction but the buds had been under a sulphur burner and it leaves a bad taste. Is there anyway of filtering sulphur out of the final product?

  158. Posted by Dayzt on December 28, 2012 at 11:08 AM

    Hey there GW – been doing a ton of reading on your blog…really great resource!! We’ve made some really nice BHO using the Honey Bee Exctractor device from (check the website) and are looking to ‘decarb’ our BHO to make it usable orally like the Rick Simpson oil… so if I’m understanding correctly, we can heat our BHO (thick, amber oil) slightly to decarboxilate it – then maybe add a small amount of coconut oil to it in that state, mix it together and syphon it to use drop by drop? Comments..? Thanks again!!

    • Yes, place it in a 250F oven or hot oil bath and watch the bubbles to keep track of decarboxylation as outlined in

      Adding coconut oil is a good idea, as it keeps the liver tied up processing it and it takes longer to remove the cannabinoids from our systems.

      • Posted by Dayzt on December 28, 2012 at 2:01 PM

        Ok, thanks! I would assume we can just use the same pyrex we’ve extracted the oil into, once the liquid butane has all evaporated..?

        (Normally, for gathering BHO for vaporizing, we do the wash with the honey-bee device, then put the pyrex into another larger pyrex that has hot water in it (a hot bath) to soften the oil – then use razor-blades to scrape up the oil and drip it into small vials. In order to do that though, we have to use a lighter so it will drip off the blade into the vial…i think that process may be burning off some of the THC..?)

        So we should be able to just take the pyrex after the butane evaporates and put into the oven at 250, watch for the bubbles to stop, then add a small amt of coconut oil to the pyrex directly, stir it in and pour into a vial or syphon it up?

        Thanks again…this is very helpful, especially since we have such a limited supply of ‘product’ to work with, so every drop counts! peace.

        • It should work as you have outlined, but it is important that a good hot water purge be used before putting the oil in the oven, because excess butane can cause an explosion.

          What we like to do instead, is use a deeper bain marie vessel to catch and boil off the butane, and then set the bain marie vessel directly in a 250F hot oil bath, with the ventilation hood going.

  159. Can you shoot bho on to parchment paper?

    Your thoughts…

    Love the info on your site


  160. Posted by Will on December 20, 2012 at 11:01 PM

    First, thank you! To Greywolf and the whole Skunkpharm team – your sharing of knowledge and experience has been such a blessing to me. I’ve loved honing my skills and brain storming some new projects thanks to your work.

    Second, do you have to constantly pull a vaccuum on BHO? I’ve seen people online use a simple hand pump to evacuate the chamber and leave it there. I’ve always done a constant vacuum but never done a side by side comparison.

    • As the solvents purge from the liquid, it will cause the vacuum to decay and atmospheric pressure to rise. It is necessary to keep the vacuum pumped down, but you can pump it down and simply valve it off under vacuum, so as to periodically shut down the pump. When the vacuum decays, simply pump it back down again.

  161. Posted by Jimmy on December 18, 2012 at 10:09 AM

    Hey guys, absolutely love the site. Definitely the most informative resource on extractions and the like.

    My question is this: my friend just bought an 8cfm vacuum pump along with a nice little desiccator. Works great. Problem is that he lives in a place that doesn’t really have the space to run butane safely. Combine this with the fact that we all ride bikes and you can see how it would be difficult to transport the 50 pound pump across town to my place just to extract outside.

    So, in order to make life easy, we’ve left the pump at his house. He would like to run the material at my place then take the non-purged oil in a container back to his place to vacuum purge.

    My concern is that waiting up to 20 minutes from the time the oil is extracted to the time that it is purged will allow the oil to harden, thereby making it difficult to fully purge the butane. The only way that I can see us removing all of the butane from hardened oil is to reheat it . This worries me, though, as I fear that the temperatures necessary to melt the oil back to the point of allowing the vacuum to work will kill flavor. The point of having a vacuum is for us to maintain the lowest temperatures possible. If this is indeed what we’re trying to achieve, does allowing the oil to harden before purging force us to use higher temps than we would if we transferred the oil straight into the vacuum chamber.

    I just worry that the dude isn’t getting the most out of his $300+ setup


  162. Posted by unlikelyhero432 on December 15, 2012 at 11:36 PM

    I am interested in using your thermos method for small high quaility personal use batches. It seems the most cost effective, straight forward, and safe. I do have a few questions. You said you add the butane pre chilled? Is this done in a refrigerator or freezer and for how long? Also When you transfer the butane mixture out of the thermos, how fine is the strainer you use? Is there a specific micron count to shoot for? And is it possible to purge all of the butane using only low heat (suspended in a constant flow of 114 degree water for example) without reaching decarboxylation and losing those valuable flavor and aromatic components which I want to preserve? A decent vacuum system is financially out of reach at this time but I still wish to make the highest quality product I can with what I can afford. I don’t necessarily care about consistency of the final product, more the preservation of flavor, aroma, and potency.

    • Posted by unlikelyhero432 on December 16, 2012 at 2:21 AM

      Also, when allowing the butane mixture to soak in the thermos, do you leave the lid off to Allow butane to boil off? Or is the whole idea to keep the thermos as sealed and cold as possible during the soak period to keep any water content tied up in ice form until the butane is removed?

    • We stick it in a freezer set at -18C/0F until it is stable at that temperature.

      I just dump the butane through a French Chinose strainer for a fast drain, because I will filter it again when I wash it out of the collection vessel with alcohol, and yet again when I winterize it.

      If I wasn’t winterizing, I would dump it through a wire strainer setting in a larger paper filter, or stretch a paper filter over the opening of the thermos. A paper filter by itself will start to clog, resulting in a lot of oil left behind on it as the flow slows to a stop.

      • Posted by unlikelyhero432 on December 16, 2012 at 8:31 AM

        Thanks for the speedy response! I see so there are a couple extra steps I was unaware of. Forgive my ignorance, but may I ask what winterizing entails? So after the butane is purged from your product you use alcohol to easily remove the product from its collection vessel, and then run it through a different screen? Then evaporate the alcohol content? Clarification would be most appreciated. (If you’d be willing to get more detailed about your process please message me at

        • Yes, we heat 190 proof to boiling and pour it in the collection tank, to dissolve and wash out the collected oil.

          We filter the mixture through a coffee filter, or through a Wattman #1 lab filter, using vacuum assist.

          We place that mixture in a freezer for 48 hours, to coagulate the waxes and fats, which we filter out using a coffee filter or a Wattman #1.

          We then evaporate away the alcohol.

          Reply sent to your e-addy.

      • Posted by unlikelyhero432 on December 17, 2012 at 3:09 AM

        I apologize for asking so much, but the more I learn, the more questions I have! Compiling all necessary information in logical order is a project in its own! I should clarify that I intend to make these extractions for vaporizing.
        I found your seperate thread detailing the winterizing process. So with this method, after the butane and plant material have soaked long enough in the thermos, you first do a fast and “crude” strain into a collection vessel to boil off the butane content?
        Then wash with ethanol and do a finer strain through… coffee filters… Before winterizing, Or just go straight to winterizing without filtering first? And when boiling off the ethanol after all waxes etc have been filtered out, what process and safety precautions should be taken?
        Another question – pushing the winterized absolute through a syringe filter would be the last step of the process? To remove any final remaining plant or bacteria particles I’d assume.
        Again I apologize for all of the questions. I want to do this safely and correctly the first time. I would like to thoroughly document my experiences for everyone else to learn from as you all have.
        Thank you.

        • Submitted on 2012/12/17 at 6:14 AM | In reply to unlikelyhero432.

          Then wash with ethanol and do a finer strain through… coffee filters… Before winterizing, Or just go straight to winterizing without filtering first?

          You can do it either way, but we usually strain twice. Some of the waxes also fall out during the first filter, so there is less to filter the second time around.

          And when boiling off the ethanol after all waxes etc have been filtered out, what process and safety precautions should be taken?

          You can simply evaporate away the alcohol, boil it off, distill it off, or vacuum it off. It is a flammable, and should be treated as such.

          Another question – pushing the winterized absolute through a syringe filter would be the last step of the process? To remove any final remaining plant or bacteria particles I’d assume.

          0.2 micron syringe filtering is the last step, and we use it only when we have reason to be concerned.
          Most of our stuff just gets coffee filter filtration, or Wattman #1 using vacuum.

          Again I apologize for all of the questions. I want to do this safely and correctly the first time. So I need to make sure I have all steps in order. i would like to thoroughly document my experiences for everyone else to learn from as you all have.
          Thank you


    • Posted by Bob Gargamel on December 18, 2012 at 9:49 PM

      I am in the midst of trying a new method…wel new to me…Blasting the butane thru the tube into a mason jar. letting the butane evap, then using everclear in the jar and putting it into the frezer for 48 hours. after that im goin to filter the alcohol and then let that evap in a warm bath…hoping it comeds out well….tryin to maximize all meds… used to doin a steam purge…hasnt done me wrong yet but still wanna learn new ways….

      • Glass doesn’t tolerate thermal stess well, so you might consider blasting into a stainless container and washing it out with the ethanol and pouring it into the fruit jar for winterization.

        I’ve had enough ah shits using fruit jars, that I am very selective where.

        • Posted by Bob Gargamel on December 20, 2012 at 1:41 PM

          I had thought of that so i am only blastin into each jar once then its cleaned and cycles to the curing room……and also i dont use high heats, at least not enough to fracture the jar, but i had thought about that prior, good point. well in the end i filtered the solution, into a pyrex dish where i then gave a few hour warm bath to it. end result amazing……Bob Gargamel from OR
          P.S. Yous have an awesome site here. So much info and innovative ideas….RIDE MIGHTY HIGH!!!!

  163. Posted by unlikelyhero432 on December 15, 2012 at 11:28 PM

    I am interested in using your thermos method for small high quaility personal use batches. It seems the most cost effective, straight forward, and safe to expirement with starting out. I do have a few questions. When prechilling your butane, do you put it ina regular fridge or freezer and for how long? Also When you transfer the butane mixture out of the thermos after it has soaked in the plant material,, how fine is the strainer you pour it through? Is there a specific micron count to shoot for? And is it possible to purge all of the butane using only low heat (suspended in a constant flow of 114 degree water for example) without reaching decarboxylation and losing those valuable flavor and aromatic components that i seek to preserve? How long would this take, and would I have to constantly aid the butane escaping process by popping bubbles etc? A decent vacuum system is financially out of reach at this time. But I still wish to make the highest grade product I can with what I can afford.

    • Submitted on 2012/12/15 at 11:28 PM
      I am interested in using your thermos method for small high quaility personal use batches. It seems the most cost effective, straight forward, and safe to expirement with starting out. I do have a few questions.
      When prechilling your butane, do you put it ina regular fridge or freezer and for how long?

      I put it in a 0F freezer, until it reaches 0F. Usually I put it in overnight.
      Also When you transfer the butane mixture out of the thermos after it has soaked in the plant material,, how fine is the strainer you pour it through?

      I use a French chinoise wire strainer, followed by a commercial coffee filter, or plan to strain it again while winterizing.
      Is there a specific micron count to shoot for?

      0 to 20 microns works well.
      And is it possible to purge all of the butane using only low heat (suspended in a constant flow of 114 degree water for example) without reaching decarboxylation and losing those valuable flavor and aromatic components that i seek to preserve?

      Any heat decarboxylates, low heat just does it slower. 114F is not hot enough, without a vacuum. Try 140F at atmospheric pressure.
      How long would this take, and would I have to constantly aid the butane escaping process by popping bubbles etc?

      ~8 to 24 hours.A decent vacuum system is financially out of reach at this time. But I still wish to make the highest grade product I can with what I can afford.

  164. Posted by Minor Wager on December 14, 2012 at 4:30 PM

    Thanks for all the great info! Been all over the forums and I’m even more confused than when I started. Seems like everyone just wants to argue shatter vs wax/butter. Inevitably, during my “super thin” film vac purging of micro batches (.5-1gm) of clear bho, there is a small point(s) created that is a little cloudy. The longer I purge, the more the clouds grow, usually from the center out until the entire sample is a “honeycomb” or “wax cookie”. I’ve aso noticed this process seems to be more frequent with higher temps and/or if I scrape or otherwise agitate the oil before the vac. Was hoping you guys have a straight answer as to what is actually happening here and how to avoid this.
    Also, after a few days storage of my glassy shatters, the outer surface becomes covered in “micro bubbles”, causing the surface to appear lighter in color and seemingly very dry. Not sure how these bubbles form at all as the oil completely hard and glassy. When handled, the bubbles break, leaving a dry dust. Some have said these is unpurged butane while others say it is moisture escaping?

    Thanks again for any help!

    • I think you get so many different answers, because no one knows for sure what is causing the waxing action, including me.

      As far as clouds, I’ve noticed that if I pull a hard vacuum on BHO at room temperature, that bubbles try to form, but can’t. As I warm it up, at about 115F, bubbles start to break free at the surface.

      I get no waxing at 115F, though I have from about 130/160F.

      What comes off first, is the solvent in random sized bubbles, followed by fizzy CO2 bubbles. They do come off in clouds and I suspect the source of your post purge bubbles.
      What temperature do you purge at and at what point do you stop purging?

      • Posted by Minor Wager on December 15, 2012 at 7:37 AM

        I try to keep my purge temp around 120F and was under the impression that I should purge until all bubbling stops. I definitely do get spots of tiny, fizzy, equally sized bubbles and alot of times, these are the starting points of the waxing. At these temps, can these CO2 bubbles be the result of decarboxylation?

  165. How long do you vac it for

  166. Posted by Oliver on December 10, 2012 at 5:59 PM

    So I am vacuum purging about 10 grams right now, with no heat.

    Is heat necessary?!

    If not, how long should 10grams take approximately?

    • With no heat at all, even in a thin film, it will take days or weeks. If you look very closely, you will see bubbles trying to form under the surface, and making bulges, but are unable to break free. If you will bring the temperature up to 115F, they will break free and start to disapate.

      • Something I’m experimenting with is using a bit of iso-alcohol in the capture/purge vessel… even a teaspoon will greatly change: boiling point, viscosity & surface tension… My working theory is that with the reduced viscosity you need less heat and/or vacuum to purge the butane and propane. Of course, you either need to dehydrate your alcohol or consider that you’ll be adding a small amount of water to your solution. By raising the boiling point somewhat, you reduce the chance of having a rolling boil which could be seen as beneficial: with a slower purge it’s easier to maintain a safe vapour concentration level; the also means that the cooling effect will be slowed-down, reducing or eliminating some condensation concerns, perhaps…

      • Posted by Derrick on January 13, 2013 at 11:30 AM

        Just wanted to say thank you for all of the great information you’re sharing. I can honestly say that I have learned more about the BHO process from your sharing than anywhere else. Maybe you can help me feel a little more confident in my lab skills by addressing one of my concerns. I purchased a 12′ glass vacuum desiccator and Robinair model#15500 pump. I would like to make a butane free extract however I am concerned about the safety of using a hot plate inside the vacuum chamber. Would you mind sharing with me your reasoning on the safety of this method so I can confidently produce the cleanest and safest BHO for our Colorado patients. Thanks.

  167. Posted by Shannon on December 9, 2012 at 12:48 AM

    I’ve searched deep and wide and this website is by far the most complete and accurate collection of information for anyone looking to do solvent extractions safely. Thank you for sharing so much hard earned knowledge and taking the time to put together an easy to navigate site.

    Have you tried using soda or “Cornelius” kegs in any of your terpenator incarnations? Stainless steel, liquid and vapor taps, a port on top you can reach your arm in, 5 gallons @ 130psi max. Great success, except the butane swells the rubber o-rings so I have to swap them out from time to time.

    Also, what advantages and disadvantages do you see in using this machine for recovery?

    • No, but I sure looked at them. The terpenator tank needs to hold both pressure and vacuum, which ostensibly makes the Cornelius keg lid design unsuitable.

      Are you able to pull -29.9″Hg on your kegs?

      The primary benefits that I see using recovery is that we can extract a gram of oil for about $0.038, don’t pollute the atmosphere, and it is a safer fully enclosed process for most folks. The advantage of using pumps over passive recovery, is speed. I can extract twice as much material in 15 minutes using a Terpenator Mk III, than I can using a Lil Terp passive extractor, in 1 hour, 45 minutes.


      • Posted by Shannon on December 9, 2012 at 9:51 AM

        Thanks for the speedy response, here are some more details on my current process.

        1. Keg filled with plant matter
        2. Keg hooked to another empty keg from liquid to liquid tap with clear line
        3. Recovery machine hooked to empty keg vapor tap
        4. Recovery tanks liquid tap hooked up to 1st kegs vapor tap
        5. Recovery machine turned on
        6. Liquid from recovery tank slowly added to 1st keg keeping under 10psi (freezes keg)
        7. When I see liquid coming through the clear line from keg to keg I flip the first keg over.
        8. Continue adding liquid butane keeping under 10psi.
        9. When I see liquid in the clear line again I know the 1st keg is full of sub-freezing liquid butane and I flip the keg back right-side-up.
        10. When I see air in the clear line again I disconnect the two kegs and fill the 1st one with liquid butane @ 80psi for a second, room temp run.
        11. I place the second keg in a bucket of hot water and leave it on the recovery machine until it reads <5psi
        12. I blow the remaining, now fairly thick, butane from the 2nd keg into a mason jar which has a bulk-head fitting in the lid and connects to the recovery machine for a 115F @ -29.9"Hg final purge.

        In my previous posting "this machine" was supposed to be a link to the brochure for the machine I'm using, but the HTML force is not with me today.

        • Thanks for sharing Shannon! I see you solved the issue with the keg lid sealing system, by not using vacuum.

          • Posted by Shannon on December 10, 2012 at 7:33 AM

            Correct, I’m not pulling a vacuum on the kegs themselves, but first transferring to a more appropriate vessel.

            What I’m most curious about is what your thoughts are on the machine I linked to in my previous posting.

            This one:


          • The important question that I am unable to answer, is whether the crank case is oil less or not. As it doesn’t say so, and it has an oil separator, I suspect that it may not be. If it isn’t oil less, the butane will eventually wash out the bearing lubrication and not only contaminate the meds, but burn out the bearings.

            The rest of the specs look good and the -30″Hg capabilities is impressiove. You might contact Snap On directly and ask whether it is oil less!


  168. Posted by Paul Thacker on December 7, 2012 at 1:35 AM

    “While we use 180F to vacuum purge a raw oleoresin, adding heat isn’t necessary when thin film vacuum purging raw oleoresins redissolved in ethanol. The alcohol will boil away under 28.5″Hg at ambient temperatures, as will the water that is left behind, even without adding any heat.”

    can you explain this to me a little furthur? I struggle with purging for some reason, with both techniques vac and straight low heat… Ive been told disolving in alcohol and evaporating doesn’t help the process, and have had that experience myself…. please help me! D:

    • Not sure that I understand the question, but the point of the paragraph in question, is that alcohol and water both boil at ambient temperatures in thin films under vacuum.
      The reason for dissolving in alcohol, was to winterize a non polar extraction, which definitely helps purify the essential oil, but it is at the cost of some terpenes. The price of taking out the plant lipids and waxes.

      • Posted by Paul Thacker on December 7, 2012 at 6:52 AM

        let me ask a different question then… i have a bunch of slightly unpurged oil that i want to refine down to a safer state… the purging process has taken a toll on it and it is hard and taffy like even when warmed to 130*. what would you suggest me do? Vac is out of the question because mine doesn’t work. I struggle with all of this biochem stuff, i just want safe medication to consume. I’m so confused because i follow the purging directions word for word :(

        • Are you going to vaporize it or take it orally?

          • Posted by paul thacker on December 8, 2012 at 9:01 AM

            I was hoping to vape it

          • Safe to vaporize is easy.

            For starters, n-butane is non toxic at the levels found in poorly purged oil, it just tastes bad.

            We can taste butane at levels far below levels of toxic concern, so if you are purged to the level that you can’t taste it, you are more than safe.

            As you are planning to vaporize the oil, you have a couple of easy options available to you.

            The first involves placing the oil in a 10″ Pyrex pie plate, on a 130/140F surface, until it purges to the desired level by taste test. About 4 to 24 hours.

            The second involves placing it in a suitable container, and placing that container in a 250F oil bath and watching the bubbles.

            The first multi sized bubbles to come off will be the solvent, and the small equally sized fizzy bubbles will be CO2 from decarboxylation. As you will be vaporizing the oil, you don’t need it decarboxylated, so as soon as only the small fizzy bubbles are left, remove it from the hot oil and cool. That takes about 15 minutes.

          • Posted by Kendall on December 8, 2012 at 2:36 PM

            I am having many of the same problems as Paul it seems. In my case, I would be vaporizing. What would I do?

          • How does my answer to Paul work for your case?

          • Posted by Paul Thacker on January 8, 2013 at 11:41 AM

            Now I have the same problem but wanted to cook with it crockpot style… is there anything i need to do to it before? is the residual butane harmful to me when ingested this way? Thanks for all your help!

          • Be sure your Crockpot has sensitive enough controls, as most don’t, and get a quality thermometer. We like the Cuisinard, and the Rival fondue pots for this purpose, and use a mercury lab thermometer, a digital, and a laser pyrometer to measure temperatures.

            Residual butane is more of an issue of bad taste at the levels typically found in underpurged BHO. If you set the oil pot at $250 and pull it as soon as the random sized solvent bubbles stop rising, it will also be below sensory threshold.

  169. Posted by James jackson on November 27, 2012 at 10:45 PM

    Wow you are very smart with ur oil extracting.I have been trying different methods and was wondering without using heat, and letting my extract sit out for a week or two and let the butane evaporate on its own. Would this work?

    • It would work, I don’t know what the time line would be.

      At a given atmospheric pressure, purging is time at temperature, so less temperature equals more time.

      Once the surface has solidified and skinned over however, it takes a lot more time. Enough heat to keep the surface plastic or liquid, will speed things along.

      It takes less time if the surface area is large, and the film thickness small, so that the butane molecule doesn’t have as far to travel.

      It also takes less time if you blow filtered air against the evaporation surface, to keep the enriched layer blown away.

      It takes less time if you drop the atmospheric pressure, by using vacuum.

      We like both low heat and high vacuum, using 115F @ -29.9″Hg, for maximum retained carboxylic acid.

  170. Posted by nate on November 19, 2012 at 11:10 PM

    Wow nice oil! I make oil myself for our local co op but I have been on a mission trying to get my oil clear! Having issues please e mail me I have a question

  171. Posted by Debbie on November 16, 2012 at 4:31 PM

    Hi, I’ve been using Rick Simpson oil for osteosarcoma in my sinus area. It’s been hard to find lately and ended up with this small square of bho. I was putting a small drop on a small piece of bread. Can I ingest the bho in the same way?

    • Yes, or you can mix it with a little vegetable oil so as to be dropperable.

      The oil also ties up the liver for awhile, which keeps it from breaking down the cannabinoids as rapidly, thus increasing apparent potency. You might achieve the same thing with bread, by dipping it in olive oil, after folding it around the grain.

  172. HEy there! quick question about bho color and consistency…

    i have been making bho for a while now, i have done many different processes for extraction and purging. from pumps to rapid heat from below to rapid heat from the top. my question is, How do you get orange chunky wax? i can easily make pure golden wax that can be handled if your quick about it, but can also be extremely adhesive if you slowly push into it. i also make a lot of wax that is more like a hash texture, its soft and somewhat crumbles to the touch. the flavor and high of each is about the same. only thing i change is the process and those two types are all i can get to come out. i only use premium trim, no shade leaves, lots of kief. i use a large stainless steel tube that hold around 100 grams of trim. i crush the trim but dont grind it down, never put more than 3 cans through one tube, usually get about 11 grams per tube. what can i do to get the solid orange texture?

    thanks for all the help!!!!

    (Michigan MMP)

    • The oil has to remain in carboxylic acid state to stay hard, smooth and waxy to the touch at room temperature. We vacuum purge the raw BHO oleoresin extraction from prime bud at -29.9″Hg and 115F to get our best results. We warm it slightly to remove it from the 6″ Petri dish, as it is too brittle otherwise.

      Younger material is lighter colored, and decarboxylated material is not only darker, but runnier and stickier.

  173. Posted by Dr. Hunchback on November 12, 2012 at 5:53 PM

    Hi! I’m loving this site. There’s sooo much great information here. But, I have a couple of questions regarding your thermos BHO extraction method.
    First, it appears from the photos that you’re using a 12oz. thermos. Is that correct? Also, do you gently pack the thermos with material the same way as you would a Flow Through Column? And finally, how many cans of Butane does it take for each extraction? For the first and second run?!
    Thanks again for having such a great site. You guys rock!

    • Thanks for the good thoughts!

      We use whatever sized thermos that we run across at Goodwill, which we pack more lightly than a column. Pressed firmly, but not tightly.

      I add butane untill I am about an inch above the plant material for all packs.

  174. Posted by M C on November 12, 2012 at 5:07 PM

    Hello, thanks for the mother load of info. Question: I remember back in the day reading about extraction and enhancement techniques, one of which was to soak the plant material in water for a day, then dry and process, the idea being that you would leach out most of the water soluables first. Seems like this would help with the Butane and water soluables issue, yes?

  175. Posted by taylor on November 9, 2012 at 2:54 PM

    what vacuum pump do you use when you do your runs?

  176. Can you please explain what causes the oil/shatter to become budder/earwax? I can not find a straight answer really on the subject

    • I’ve never heard an answer that I embrace either bro! It looks like an emulsion to me, but not everyone agrees with that assessment.

      A good question, which I’ll pass on to Joe, our biochemistry braintrust, and ask him to share his thoughts.


      • I’m starting to believe that also because before the alcohol had completely evaporated I stirred a small section lightly of my winterized bhoand it buddered. The taste of alcohol never left. Budder tends to hurt my sensitive throat and tongue more. So the question becomes is the butane emulsion safe to consume in large quantities, which is nearly impossible to answer because it will budder with varying amounts of tane.

        • n Butane has a LC50 Inhalation Vapor Rat, of 658000 mg/m3 4 hours. It is a simple asphixiate and not of health concern at the levels you would find them in oil that looks solid, but hasn’t been fully purged. It’s low toxicity is why n-Butane is often used as a food propellant.

    • Posted by on November 8, 2012 at 11:18 PM

      look up nucleation

  177. Posted by jt on October 19, 2012 at 7:46 PM

    does winterizing remove any unpurged butane?

  178. Can you explain the difference between ISO and n-butane and why the latter is superior?

    • ISO, made with the polar alcohol Isopropyl, has more polar elements in it than the non polar butane.

      Not sure I would say that it is superior, but it is easier to extract pristine oils with non polar butane, because it doesn’t pick up as many water solubles or chlorophyll, and it is easier to purge, due to its low boiling point.

      The test panels actually rated QWET and QWISO from cured material, more flavorful than butane extracts from cured material, because it has more floral undertones. All three were rated effective, to incapacitating, depending on the tolerance and dosage.

  179. Posted by Marc on September 29, 2012 at 2:48 PM

    When mentioned above, most flavorful from yourself and test panels, Do you mean literally, immediately frozen when picked? Or cured for 5-7 days then packed in a Column to freeze? Sorry I’m confused….. I just want to get it right before I start a trial run!

    • Posted by Marc on September 29, 2012 at 3:54 PM

      I just read you recommend a thermos if freezing my material….

    • Cut up and pack in the thermos or column right off the plant, and place in the freezer. Make sure the material has no water standing on it, as it will freeze and cover up the trichomes.

      • Posted by frank l jones on July 28, 2013 at 5:37 PM

        I recently did try the thermos soak extraction ,
        using dried cured frosty bud and I was pleased(smile) now im about to do the fresh cut frozen using the thermos soak so my question is do we use the same soak times when using fresh cut frozen flowers? and is it possible to rerun a 2nd time? Looking forword to hearing about this
        thank yas and hope all is well

        • I would suggest a 30 minute soak, followed by a 1 1/2 hour soak with the fresh frozen. You can run it as many times as it takes to get the trichome heads, as long as you keep it frozen and a 100X microscope will tell you when you are done.

  180. It means that not everything was volatilized. Periodically you should heat your nail to glowing red to turn all remaining organic compounds to CO2 and water vapor, like you do in a self cleaning oven at about 700F.

    I lightly brush off the light gray ash that forms during use, but never clean my nail, skillet, or wand beyond that super heat and self clean.

  181. Posted by to on August 29, 2012 at 3:31 PM

    you cant used his info without permission.

  182. Posted by to on August 29, 2012 at 3:30 PM

    You guys have used the TAMISIUM info and videos! SO sad!!

  183. [...] Here is the best write up I've ever seen, thx Gray Wolf Reply With [...]

    • Thanks for your enthusiasm and good thoughts! Hope you find stuff that is useful!

      Peace GW

      • Posted by justin on August 15, 2012 at 6:03 PM

        Where could I get Rick Simpson Oil in Bay Area.My mom has a colun cancer stage 2 so I would like to buy for her.
        Thanks GW

        • Sorry, I don’t know where to get oil in the bay area. You might try posting on a medical forum like, and ask that question.


        • Thanks for your information.! Was wondering about any extractions done with any other fruits or flowers to combine them together to enhance the floral flavors? An it would effect the Thc ?
          Thanks from all @ 3mc delights
          Hey Justin, rick just call me an sent me your Simpson me an cure Mom!

          • No but it is on the project agenda to mix in other terpene sources, so as to replace monoterpenes and sesquiterpenes lost during purging. An alternative is to just purchase and blend in other essential oils, but extracting them along with the cannabis sounds like a better idea.


  184. Posted by Mane on August 5, 2012 at 9:59 PM

    Awesome write up! How did you make that stand thing for the glass columns? I’d be really interested in making one, my arms have been getting tired!

  185. Posted by TOOOOOOooooooooo on August 3, 2012 at 9:37 PM

    Awesome article! i’ve allread used your thermos method several times with solid, consistent yields. One question though and I know you already touched on this but I still dont fully understand. Do the effects and medicinal qualities carry over when converting into oil? What im asking is; is there any point in me buying, lets say, blueberry, when its going to be the same high as oil made from Purple kush, or any combination of strains for that matter?

    • The essential oil from each of the strains tastes and effects differently, because the mixtures are all slightly different. Like bud, it works best if you select a strain that works well for you specifically.

      Having said that, they all work for my pain, just some better than others. Trainwreck works best overall for me, but some like C-99 are more uplifting, and others like Hippy Chick make me want to eat everything in sight.


      • Posted by TOOOOOOooooooo on August 14, 2012 at 1:07 PM

        Hello again and thanks for the incredibly helpful information! I’ve encountered a rather troubling problem I was hoping you would be able to help me solve. About a week-week and a half after making my first batch of oil, I went to use some and (for lack of a better way of describing) it had turned into a mellow yellowish color with the consitency of paste/dust. I have been storing it in a small plastic bag in an airtight mason jar. When I first made it I had it on a piece of wax paper for about a day-2 days. I recall reading somewhere that oil should not be stored on wax paper, or parchment paper but I can’t remember what the article specified. Is this possibly the problem? As well after applying heat to the oil/paste/dust, it seemed to return to its golden honey oil form.

        Again thank a ton for all the great info, your research has giving me boat loads of confidence in my minimal scientific ablity and experience! If you need anymore info on my process please ask.

        PS. Up until now I had not seen any problem with the oil, mind you that last time I checked on it was 2-3 days ago.


  186. Posted by montroller on July 14, 2012 at 7:22 PM

    Hey I just wanted to say thanks for the great information. I do have one question about properly freezing the material prior to extraction. I am using an open ended tube for reference. You mentioned that it should be frozen in a dry environment to avoid freezing the buds over and decreasing yield. So I am wondering if a freezer is suitable for this or if I should use dry ice? Also should I pack the tube and freeze it all packed or freeze the material and pack after? My plan was to pack the tube almost full and fill the last part with dry ice, let that sit until the dry ice has frozen the material inside the tube then pack the remaining portion and run it as quickly as possible. Any feedback or insight is very helpful.

    • You’re welcome!

      With our humidity, it works better for us to pack the tube and then freeze it. It exposes the material to less humidity to form ice.

      For running fresh frozen material, consider using a thermos instead of a tube. It allows you to extend the soak time to compensate for the lower temperatures.

      As far as dry ice, chilling the material slows down the extraction rate and it is only necessary to chill it enough to keep the water tied up as ice. I personally have never tried to use dry ice in a tube, so if you do, perhaps you can report back.

  187. We appreciate all the updates and fresh photos. Our followers really loved your plant turnover and dipping fixture.

    • Thanks bro! Glad it interests more folks, than just the nice lady whom I whomped it up for!

      It is based on the same principles that we used to build large mold turn over devices in the aerospace investment casting industry. You can rotate objects weighing tons freely with one hand, if you just pick their neutral axis.

      It also isn’t all that big, so it can also easily be built from scraps of lumber, as was mine. The pinion hanger strips and the upper spreader beam were made out of scraps of unistrut, the aluminum angle was from short pieces of scrap, and as I recall, all I had to buy was the long pinion bolts, nuts, and washers, plus the hanger ropes.

      I have my own junk piles in two garages and my basement, but sometimes also pick up scrap metal at $0.50/lb at Clackamas Steel scrap yard here locally, so do check your scrap yards before pundling down cash for new stuff, if you don’t have what you need squirreled away.

      Also check your local Goodwill and Salvation Army stores for cheap components before starting any project, and you will be amazed at what you discover if you look at everything from the standpoint of what can I do with this, instead of just what it is.

      It can also be a fun way to spend some quality time with like minded brain trusts.

      Hee, hee, hee, snicker, snark, snort, ahwoooooooooooooooooooooooooooooooooooooooooooooooooo!!!!!!!!!!1

  188. [...] nuts… BHO ExtractionPosted by Skunk Pharm Research,LLC. Butane Honey Oil, or BHO, is the essential oil from the cannabis [...]

  189. Join for more from the Skunk Pharm


  190. How many times will you purge your oil in the vacuum with heat? Just the once you’ve noticed?

  191. Thanks for the good thoughts!

  192. Thanks for the good thoughts but no experts here, only more advanced students. Do feel free to take what you can use and discard the rest!


  193. Posted by cooper on October 8, 2013 at 10:58 AM

    do u still update the site i had a few questions

  194. What are your questions?

  195. Posted by Organic alchemist on March 4, 2014 at 3:53 PM

    Bump !!

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