We’ve already covered the basics of cannabis extraction and the three most common extraction methods used in the cannabis industry. Now let’s take a look at how raw cannabis extract is further refined to create familiar products like edibles and vape oils.


The goal of extraction is to remove and concentrate the most valuable organic compounds—cannabinoids, terpenes, and to a lesser extent flavonoids—from the cannabis plant. But the initial solvent extraction also removes less desirable compounds, including lipids or fat molecules.

Winterization is the process of dissolving crude cannabis extract into a polar solvent such as ethanol, and then chilling the mixture to below freezing. This causes the fat molecules which have a lower solubility in the chilled solvent to float to the top of the mixture where they can be removed by filtration. The result is a more pure and stable cannabis extract.


While most of us are familiar with the main psychoactive cannabinoid, tetrahydrocannabinol (THC), the cannabis plant actually produces tetrahydrocannabinolic acid (THCA), the acidic form of THC. THCA is the dominant cannabinoid in fresh cannabis. However, unlike THC, THCA is not psychoactive.

The process of decarboxylation removes the carboxyl group (COOH) from THCA, converting it to THC. This can occur naturally over time as the plant ages and is exposed to sunlight. It can also happen rapidly when THCA is heated during the process of vaping or smoking.

Cannabis extract destined for edibles or any type of oral administration must be decarboxylated to ensure the final product is psychoactive. Heat generated during the extraction process may convert a proportion of an extract’s THCA to THC. However, not all extraction processes use heat and additional post-extraction processing is usually required to ensure a 100% conversion.


If the manufacturer wants to create a more concentrated form of cannabis extract, they must next perform a distillation step. Like extraction, there are many different methods for distillation. However, they all share the same basic principle.

Distillation uses differences in boiling point temperatures due to varying molecular weights to separate compounds in a mixture. Depending on the method used, the resulting distillate can form a translucent, semi-solid, sap-like substance or a glassy solid that’s amber in color. In either case, cannabis distillate is highly concentrated in THC.  

Making Isolates

Products containing CBD-rich extracts made from legal, low-THC hemp varieties of cannabis are popping up all over the internet. Many CBD companies offer a white, powdery substance known as CBD isolate.

Isolates are typically between 98-100% pure CBD and require additional refining after extraction. Chromatography techniques allow manufacturers to further purify individual cannabinoids. You’re more likely to see CBD isolates because their purity ensures the THC concentration remains below the federal legal limit of 0.3% by weight.

Understanding the science behind cannabis extraction and processing can help consumers understand exactly what’s in the products they’re purchasing and see through marketing gimmicks. However, there’s no substitute for comprehensive cannabis product testing to ensure the purity and safety of your cannabis products.