This is a commonly used method because it is safe, provides a clean end product and gives a high degree of extraction. Cannabis extraction uses pressurized carbon dioxide (CO2) to extract cannabinoids and other phytochemicals. At certain temperatures and pressures, CO2 acts as a solvent. The process goes like this: the extraction machine lowers the temperature of CO2 to -56 degrees Celsius while increasing the pressure to 5 bar. Under such conditions, carbon dioxide passes the so-called “critical point” and acquires supercritical properties. It acquires the properties of both gas and liquid at the same time. Like a liquid, it retains its density and can dissolve materials, and like a gas, it can fill a volume and penetrate materials. When CO2 is in the supercritical state, it is ideal for chemical extraction because it does not cause denaturation or damage to the substances being extracted. After extraction, CO2 is easily removed from the material, it is only necessary to reduce the pressure and CO2 evaporates from the material without residue, leaving pure CBD oil without impurities. For this reason, this method is suitable for medical applications as it can guarantee that there will be absolutely no residual solvent in the final product.
The advantage of this method is the speed of extraction and ease of material extraction. By varying the pressure and temperature parameters, the extractor can be more selective and accurate in terms of the exact content of the extract and the content of other substances such as waxes, fats, chlorophyll, which may end up in the final product. This method is suitable for extracting specific cannabis compounds. The yield of the CBD product with this method is also higher. The CO2 after extraction can be used again, so no production waste is generated. Of course, this extraction method requires special equipment, which takes up a lot of space and is expensive. Some disadvantages can be considered that some useful substances, such as terpenes, are not released during the extraction process and do not enter the final product. Of course, it is possible to isolate the terpenes separately from the cannabis material and add them separately to the final product. But perhaps not all manufacturers do this.
Subcritical means that extraction occurs below the “critical” point, at a lower pressure than supercritical extraction. This method gives a lower yield of cannabinoids, but they are of higher quality. Terpenes, essential oils and other sensitive materials are preserved. Also, the resulting extract contains almost no waxes. But due to the low yield of the product and the fact that the process takes much longer, the resulting extract can be significantly more expensive.
