Different methods of cannabis extraction serve different purposes, which means they involve different extravagancies that need to be monitored with special attention to maximize their efficiency.
Supercritical C02 Extraction
Supercritical CO2 is the preferred method by many because of its toxin-free nature. This extraction is the safest both for users and the environment. Extractors, however, choose to take this path to their desired concentrate for reasons that go beyond safety and into potency. CO2’s “critical” point of compression is approximately 88°F which is well below the deactivation temperature of cannabinoids and terpenes. This means CO2 reaches the desired state before anything else, providing room for creative freedom. Given that they know at what temperature and pressure each terpene, cannabinoid, and wax separate from the source material, extractors can choose which of the sort’s flavors and distinctive features to bring out, giving the concentrate their own personal spin.
But there’s a catch – many believe in removing unwanted materials such as plant fats, this longer and more aggressive purification process can cause collateral damage on the cannabinoid and terpenoid profile of the extracts. This is why some deem this method of extraction inefficient. You need to monitor for the happy medium between purity and potency.
Many believe ethanol extraction, on the other hand, borrows the best of CO2 and butane extraction. Gene Galyuk, principal engineer of Capna Labs, a California-based extraction company founded in 2014, certainly does: “We knew that we needed a solvent as safe as CO2, but as efficient as butane.”
But ethanol doesn’t have it all either. “The biggest hurdle by far was ethanol’s polarity,” Galyuk explains. “A polar solvent [such as ethanol] will readily mix with water and dissolve water soluble molecules. Chlorophyll is one of those compounds which will easily co-extract when using ethanol as a solvent.”
Chlorophyll gives the extract a distinctively bitter, grassy flavor which is hardly to anybody’s taste. Furthermore, being alkaline aside, its medicinal properties are not strong. Cannabinoids come off quite easily from the source material when soaked in ethanol, which makes prolonging the process unnecessary and even counter-productive – you would get just a little more cannabinoids at the expense of having a lot more chlorophyll in your end product.
This method is powered by the interaction between chromatography media such as silica and the different cannabis compounds. Substances unwanted in the final product have stronger reactions to the silica which slows them down toward the final destination while THC and CBD react weakly to the silica and travel faster through it as a result. This is how the separation occurs.
As you probably guessed, once again, there’s a “but”: greasy, nonpolar compounds such as terpenes, and even cannabinoids, can end up traveling with roughly the same speed and become harder to separate.
As you can see, each process has its advantages and disadvantages, and through monitoring, extractors can maximize the pros and minimize the cons.