There’s been a lot of interest in turning less than appealing concentrates into a quality product. Recently we were loaned a Kugelrorh and tasked with standardizing a method to produce a consistent product.
The basic work flow prior to distillation is very important. There are two steps that must be completed prior to short path; winterization and decarboxylation.
Dissolve the extract in 190-200 proof ethanol at a 10:1 to 15:1 ratio depending on particulate load. Chill to at least -40c but ideally -80c for 24 hrs. Filter in a buchner funnel using coffee filters on top of 2um fast flow filter paper. Distill alcohol in a still or rotovap.
Follow as above, except place dry ice directly into the ethanol solution and maintain for 2 hrs at -80C then filter immediately.
Heat oil to 121c on a heated stir plate until all of the tiny bubbles are gone. If you get impatient and remove too early you’ll likely have issues during the following steps.
Short Path distillation equipment:
A simple boiling flask with Vigreux condenser can be used to produce distillate. This is the most economical option but, also has the lowest yeilds.
A good example of can be found on Google or here.
The next step up in production efficiency is the Kugelrorh thin film distillation apparatus. Currently there are 3 companies manufacturing these; Sigma Aldrich, Buchii and Jkem.
The next step up in production is the wiped film evaporation. A good example would be a Pope or similar apparatus.
A similar but, larger unit that uses a rolled film rather than a wiped film would be the Terp Trommel.
There are 3 distinct fractions in this procedure; 1) the light volatile’s that have boiling points below or slightly overlapping 2) the Cannabinoid’s and 3) non volatile’s.
Dual fraction systems, those that separate one fraction at a time, temperature is raised gradually to remove the volatile fractions in order of their respective boiling points. Generally the lowers are removed below 185-195C depending on level of vacuum and film thickness. The Cannabinoids are separated next up to 260C in some devices and the black non volatile fraction is discarded.
Three fraction systems, such as the Terp Trommel, separate all three fractions in a single distillation step. Accomplishing this feat of engineering requires close attention to thermodynamics and residence times to separate the volatile’s from non volatile’s in continuous operation.
Distillates can be re-distilled several times for improved color and stability. Mono-terpenes or vape ready flavorings can be added for improved flavor and viscosity for vape pens. Distillates in the raw can be vaporized or put into edible products for improved flavor over RSO products.