According to the 2018 Farm Bill, industrial hemp with a maximum THC content of 0.3% is legal to cultivate in the United States. While the legislation didn’t legalize CBD, it ensured that almost every state tolerates cannabidiol products derived from hemp.
Brands that sell CBD oil must complete a complicated process to extract the compound from the hemp plant. Whether it is a CBD oil 300mg product or one containing 5,000mg, there are three popular extraction methods:
- Supercritical CO2 extraction
- Oil extraction
- Liquid solvent extraction
Top-rated brands like Premium Jane primarily utilize supercritical carbon dioxide (CO2) extraction, and it is this method we’ll focus on in the article.
What Is Supercritical CO2 Extraction?
It is a processing technique that involves pressurizing CO2 under controlled temperatures to ensure hemp compounds such as cannabidiol and terpenes are extracted from the plant. It is regarded as the gold standard of extraction in the CBD industry because it leaves behind a ‘clean’ product.
Indeed, companies have utilized CO2 in commercial applications such as oilseed extraction and coffee decaffeination for more than 40 years. It is relatively inexpensive, non-toxic, and non-flammable. That being said, the equipment used to complete the process is fairly expensive, which is why so many low-grade CBD companies avoid using it.
Sadly, research shows that CBD products are often mislabeled, with brands cutting corners to get their items on the market. CBD oil taken from hemp and extracted using supercritical CO2 extraction tends to be much higher quality.
The Supercritical Process
Carbon dioxide is usually a gas. However, when it is placed under pressure at approximately 1,071 pounds per square inch (psi) and heated above 88 degrees Fahrenheit, it takes on the properties of the liquid and the gas and becomes known as a supercritical liquid.
CBD manufacturers normally use a machine called a closed-loop extractor. It is a sophisticated piece of kit consisting of three chambers, and it manipulates the CO2 states while extracting CBD and other compounds from hemp.
Here’s a quick overview of the process:
- It begins by placing the ground hemp into one of the machine’s chambers
- The solid carbon dioxide (dry ice) is pumped into the machine and gets converted into supercritical CO2 as it enters
- The supercritical CO2 goes through the plant matter and extracts its compounds
- This mixture gets pumped into another chamber where the contents get separated
- The oil is collected in the machine, and the carbon dioxide returns to the original chamber, where it is reused
One of the main benefits of supercritical CO2 extraction is that the process kills off contaminants such as mold and bacteria. Crucially, other extraction methods fail in this mission. Therefore, CBD oil taken from hemp via supercritical CO2 extraction is usually the cleanest form of the product on the market.
Winterization
The standard CO2 extraction process involves extraction to get the crude product and a post-extraction phase where the company does a cleanup to get refined CBD oil. Within the post-extraction process, many organizations utilize winterization.
Winterization involves removing waxes and fat from the hemp extract. The manufacturer dissolves the CBD oil from the CO2 extractor in food-grade ethanol and chills the new mixture at -4 degrees Fahrenheit. At this low temperature, the waxes and fats are less soluble and precipitate while the cannabinoids remain. Finally, the company filters the fats and waxes before removing the solvent.
However, ethanol-based winterization comes with many downsides. Apart from the inefficiency of the process, it is virtually impossible to remove every trace of ethanol. Fortunately, there is a new winterization process that is performed using CO2 during the primary extraction. Green Mill Supercritical, operating out of Pittsburgh, has developed the patent-pending process called Real-Time Winterization.
Instead of spending four days to complete the process (one day for CO2 extraction and three days for winterization), Green Mill can do it in a single day. The resulting product is clean, bright, and filled with cannabinoids! While standard ethanol winterization can leave behind up to 10% of cannabinoids in the waxes, the Green Mill method recovers up to 99% of compounds!
Final Thoughts on the CBD Oil Extraction Process
The above is a highly simplified version of an extremely sophisticated process. Supercritical CO2 extraction takes the most relevant compounds in CBD oil from the hemp plant. It is the cleanest extraction method. As the equipment used in the process is expensive, CBD oil created in this fashion is usually more costly than products created via solvent extraction.
Winterization gets rid of unwanted waxes and fats in CBD oil, and there is a new process available that slashes the time it takes to winterize the oil properly.