HYDROCARBON EXTRACTION, EXPLAINED
First it was THC, then CBD content, now the buzz of the cannabis industry is centred around terpenes. Terpene profiles in cultivation and terpene retention in extracts are a big part of what we do at Greybeard. But what does that mean for everyday cannabis users?
Take a moment and think about the aroma of orange zest in a freshly-baked scone, or the complexity that a sprig of rosemary can add to a sauce or a marinade when you’re cooking. You can thank terpenes for all of these. Terpenes are responsible for many of the aromas we enjoy with our fruits and vegetables, and they’re present in most plants.
Greybeard Cannabis’ team focuses on the method that best preserves the natural aromas of cannabis plants, called hydrocarbon extraction. Mat Pridham, Director of Extraction for Greybeard, decided to go that way after looking at the breadth of cannabis extracts that are now available on the legal market. “The majority of other extracts we’re seeing are either distillate-based or CO2-based,” Pridham points out. “What makes our product better than those two is terpene retention.”
Hydrocarbon extraction is a solvent-based extraction process that uses hydrocarbons like butane or propane to remove compounds like cannabinoids, terpenes, and flavonoids from the raw cannabis material. The reason that butane and propane are useful for terpene retention is the low boiling point needed to achieve extraction. The boiling points of butane and propane are around 30.2 degrees and -43.6 degrees fahrenheit, respectively.
Pridham compares this to ethanol-based extraction saying: “alcohol, which is used to make ethanol for distillate extraction, unfortunately boils at around 70 degrees celsius, and terpenes start boiling off at around room temperature. You’re pulling off all of the volatile constituents and just leaving the heavier stuff behind.”
Similarly, he points out that CO2 extraction is “180+ degrees celsius and thousands of PSI, and that converts the terpenes to their oxidized components, terpenoids.” Terpenoids, according to Pridham, “don’t always maintain that pleasantness —you often get a more astringent version.”
Hydrocarbon extraction maintains the chemical and flavour profile of the cannabis plant better than other extractions. Since terpenes likely also interact with the endocannabinoid system in the human body, this could even contribute to the entourage effect that you hope to find in any quality cannabis product. This means that maintaining terpenes in cannabis production is important for getting the most out of your extracts. Pridham points out, “one strain might make you hungry, another makes you energetic, and another might put you on the couch. This has a lot more to do with terpenes than any of the cannabinoids present.”
As great as hydrocarbon extraction is, it might not be wise to try it at home. While butane is labelled GRAS by the FDA (“Generally Regarded as Safe”), it is still highly flammable and requires well-maintained equipment and knowledgeable, hands-on production staff. To enjoy hydrocarbon cannabis extracts, Greybeard products that are overseen by pros like Mat Pridham might be your best bet. Pridham concludes, “Our goal is to deliver as true a representation as we can, and my wholehearted belief is that the only way to do that is with cold hydrocarbon extraction”.