Since the legalization of hemp cultivation after the farm act of 2018, there are many CBD products available in the market making it difficult to buy a good quality product. Some of the popular products are oils, tinctures, vape oil, topical, etc and the quality of cannabidiol contained in them is dependent on the extraction method used. There are multiple extraction methods, and the following are some of the methods used for CBD extraction.
CO2 extraction is considered by many to be a really good method to produce CBD rich extracts. Here, carbon dioxide under high pressure and low temperature is transformed into a liquid that is passed through the plant materials to extract cannabidiol CBD and other compounds. This method has an efficiency of 90% and you get a highly concentrated pure end product. However, it requires complex equipment making the process expensive and most of the high quality and reputable brands use this method.
Compared to the previous method, ethanol extraction is a less expensive process and used by many companies to make CBD extracts. This is because it can also produce high-quality end product despite its lower cost but requires more complex post-extraction processes to get the final product. Here, a polar compound like Ethanol is used as a solvent as it is water-soluble and dissolves water-soluble compounds including the cannabinoids from the hemp plant material. But, one of the drawbacks of this method is that it also extracts chlorophyll and it is a dark colored liquid with a bitter and grassy flavor. Post-extraction methods such as filtration are used to remove the impurities such as chlorophyll to get the final pure product.
This is an older method where a light hydrocarbon solvent such as butane, propane, isopropyl alcohol are used to extract CBD oil and this is because they have low boiling points. It is a cheap and easy method having a variety of issues making it a non-ideal extraction method. One of the biggest reasons is, the final product has high THC and low CBD content along with it being an inefficient process.
Lipid Extraction is a least used method where lipids or fats are utilized to extract the cannabinoids from the hemp plant materials. Very often, coconut oil is used instead of strong solvents and you may find it used in boutique company products.
Purification Of Crude CBD Extracts
The crude or raw CBD extracts will have a lot of impurities such as chlorophyll along with other cannabinoids and terpenes. A process called winterization is used to further purify, where the CBD extract is mixed in 200 proof alcohol and frozen overnight. The cloudy mixture that you get, is filtered through a paper filter into an extraction jar. The alcohol from the final product is removed by warming until it evaporates. Therefore, when purchasing CBD medical products choose extraction methods that are safe.