CO2 Plant Extracts 101

August 8, 2017

–by Scott Sondles, west coast sales person at Apeks Supercritical

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Carbon is the center of life, the #1 element in the universe, and the top choice for cannabis and botanical extraction. From Rosemary to Mary Jane, CO2 extractions are replacing conventional plant extracts and changing the way cannabis is being consumed.

CO2 extracts are the highest quality plant extracts on the market and are replacing steam distillation and synthetic solvent methods every day. Herbs are extracted using subcritical (liquid) or supercritical CO2 that creates a pure and honest extract. CO2 extracts are the perfect addition for cosmetics, edibles, healthcare products, and nutraceuticals.

Plant oils, pigments, and resins are pulled into a high concentration of plant material that is unaltered by thermal degradation or harsh chemicals.

CO2 extracts can be used to make virtually any type of cannabis extracts, such as oil, shatter, budder, or wax. CO2 extraction machines can be extremely tune-able and users can change parameters (pressure and temperature) to get a wide range of end product. The end product can vary depending on plant material, pre-processing techniques, temperature, pressure, flow rates, and time. CO2 extraction is also best suited for terpene preservation and does amazing job of capturing the full flavor profile.


Not all CO2 extraction systems are made the same and many CO2 systems can actually ruin your whole plant extract. When it comes to CO2 extractions, your separation method, pressure, temperature, and runtime all play a role in the antioxidant activity of your end product.

CO2 extraction systems allow operators to work with more variables during the extraction process than conventional methods, which in turn, allows them to safely create the desired end products. Gone are the days where the only option was using dangerous butane extractions. We are just scratching the surface into the potential of the tune-ability of CO2. The cannabinoid THC is the least soluble cannabinoid while rare cannabinoids such as CBG and CBN have the highest solubility.

What is supercritical?

Supercritical is the 4th state of matter behind solids, liquids, and gases. Supercritical states do not occur naturally, but when you put a bunch of engineers in a room, they can do just about anything! Turns out the supercritical state of CO2 provides the perfect natural solvent for extracting volatile plant compounds such as terpenes and cannabinoids (THC, CBD, CBG etc.). At roughly 1,100psi (pressure) and 87 degrees Fahrenheit, CO2 becomes supercritical. These low temperatures combined with a natural solvent make sure precious plant chemicals stay active.

Supercritical is a more powerful solvent than subcritical CO2 and you can see the difference by looking at the below picture. The extract on the right was created under supercritical parameters and pulled more chlorophyll out of the plant material.

What is subcritical?

Apeks Supercritical machines can also do subcritical CO2 extractions. This is an extract done on low pressure, with low temperature. These lower temps mean a lower yield (not as powerful as a solvent), but it will be a more fragrant extract with volatile terpenes. Many studies suggest that these subcritical extracts could provide more therapeutic benefits due to the higher concentrations of terpenes. Visually you can tell the difference between a subcritical and supercritical extraction by color. The extract on the left is an example of subcritical and the extract sample on the right is an example of supercritical.

Subcritical extractions take longer and do not pull out the larger molecular elements that are extracted with supercritical. The majority of Apeks Supercritical customers do short “Terp Runs” using subcritical parameters (low pressure, low temperature) to preserve the medicinal terpenes and then complete the extraction using supercritical parameters (high pressure, high temperature). These two extracts are then re-introduced after the winterization process (see video below).

If you have any further questions regarding the CO2 extraction process please contact me.