Since the legalization of hemp in the United States in 2018, farmers have legally started to cultivate CBD plants. This is the case in many other countries where cannabis that contains a THC percentage less than 0.3 is now a standard commodity in the agricultural world.
For those who are unfamiliar with the hemp flower, it’s the little flower-like part on the top of the female hemp plant. When the plant is fully grown, the flower releases cannabinoids. It is then extracted using different kinds of methods to create a variation of beneficial products. Check this reference for different examples of products.
There are many different kinds of extraction methods used by hemp farms. In order to extract the beneficial compounds from the flower, farmers should use the right kinds of equipment.
The most effective means to extract CBD from hemp plants are the CO2 and Ethanol extraction methods. Explained here:
The Carbon Dioxide extraction method is becoming an industry standard. It consists of two different stages that include the supercritical and subcritical stages; these stages refer to the Carbon Dioxide pressure adjustment that turns into solvency power.
Carbon Dioxide is pressurized from the biomass to extract CBD from the flower. During the supercritical stage the CO2 is converted into a liquid at a very low temperature of 88ºF. It’s during this stage that it’s at its most perfect to extract cannabinoids. Because of the cold temperature and the liquid form, it is less damaging to the plant matter.
The supercritical CO2 is passed through the flower. While it moves through the plant matter it extracts all of the beneficial compounds within it this includes large molecules. The contents are now part of the Carbon Dioxide liquid and can undergo further filtering.
A special separating device separates the good stuff from the Carbon Dioxide that enables it to be reused again. This also makes this method greatly economical for farms that produce large quantities.
Learn more about this method here: https://www.sciencedirect.com/science/article/abs/pii/S2212982018304220
The subcritical stage uses the same method but the extraction is much gentler and doesn’t pull all of the goodness out of the flower. Therefore, the supercritical extraction method creates higher quality CBD products that are pure.
This method is the more affordable one out of the two and is used by smaller farms. It uses high-grade solvent to pull beneficial properties from the hemp flower. Ethanol is an FDA approved risk solvent that has low levels of toxicity. This makes it a perfect class 3 risk solvent for CBD extraction.
Other solvents that can be used in this method are butane, isopropyl, propane, and alcohol.
There are two stages within the Ethanol method; supercooled and room temperature. Using a low temperature ethanol liquid for extraction is very speedy. On the flip side it can damage the terpenes within the flower making it less pure than when you’d use the supercritical CO2 method.
Room temperature Ethanol preserves the hemp flower’s wax and pigment while extracting. Even though the supercooled Ethanol extraction method is the fastest and less expensive option, it does give manufacturers a less pure product to work with.
Other extraction methods include the use of olive oil. Even though it’s a safe method it has proven to create a product that have low yields. Which as a result create a perishable product that won’t hold as many strong benefits as oils from other extraction methods.
WHAT HAPPENS AFTER THE EXTRACTION?
To get a clean hemp oil from the raw ingredient, a process called ‘winterization’ is used. It basically is a step where all the residue is removed from the raw oil. Residue like chlorophyll, lipids, solvents, waxes, and other unwanted parts are sifted out and removed.
After this process the hemp oil is clean with approximately 70%-90% CBD, terpenes, and minor cannabinoids. This oil can now be processed into many different products including topical creams, oils, vape juice, and edibles.
When you start shopping around for a CBD product derived from hemp flowers, you can investigate what kind of extraction method was used. This will give you an indication of the quality and purity of the oil.