Cannabis Extraction 101
Treed CBD is extracted using the C02 supercritical method discussed above, which is why we can confidently claim to have the purest CBD available in the UK today.
CBD oil extraction is not like growing regular fruit & vegetables, it is in actual fact really technical, high-level stuff that takes years of research, analysis and learning to get it right.
So this week, we have put our science-hats on and geeked out, so you’ll know exactly how our CBD products are made.
Let’s get down to basics
The goal of cannabis extraction is to create a product with a high concentration of cannabinoids. Simple, right? In reality, getting cannabinoids like CBD from Point A, where they’re inside the plant, to Point B, where they’re in a concentrated form is a highly technical process. Keep in mind that it requires properly engineered equipment and highly knowledgeable, skilled experts. This is high-level chemistry, not cooking. Any extraction process must be executed correctly to produce an end-product safe for human consumption—and the results should always be tested and confirmed by an independent third-party laboratory.
In layman’s terms? Think of a molecule like a lock and a solvent like a key; you want to find the perfect key.
Cannabis Extraction – Common Terms
Solvent: something able to dissolve other substances
Molecule: a particle made up of two or more atoms that are chemically bonded
Trichome: the fine outgrowths or appendages on plants.
PSI: a metric used in chemistry when describing the amount of pressure expressed in pounds of force per square inch.
Polar solvent: a polar solvent is a liquid with molecules that have a slight electrical charge due to its shape
Carbon dioxide, or CO2, is a gas found in the atmosphere. In order to create a solvent, it must undergo something called a “supercritical” phase. This means that you must compress and heat this gas in order to change it into a liquid form—that’s why the process is called a supercritical CO2 extraction.
This technology is not unique to cannabis extraction, but has been around for years as a standard extraction method for food. It’s used to produce carbonated soft drinks, as well as to remove caffeine from coffee beans in order to make decaf coffee. As the cannabis industry began to scale globally nearly 10 years ago, scientists repurposed supercritical CO2 into the industry.
Because of the recent boom in the hemp industry, this method of extraction is now the most common and advised way of extracting CBD from hemp. For CBD extraction, it is considered the gold standard, because carbon dioxide is a non-toxic substance that doesn’t leave any residue behind, a safety imperative when consuming any CBD product.
In a Supercritical CO2 extraction, the liquid CO2 is repeatedly passed over the trichome structure to extract all the cannabinoids, terpenes, and flavonoids. This is a more time-consuming process than other solvents and can take several hours.
At atmospheric temperature, CO2 is a gas. Liquid CO2 cannot exist at atmospheric pressure, and as mentioned earlier, it has to be heated to reach the supercritical phase. This means that liquid CO2 is at a higher pressure than CO2 in its gas form. Because we are pouring this liquid CO2 over plant matter, we are working with a much higher base psi, or the amount of force expressed in pounds of force per square inch.
When it comes to CO2 extraction, you need equipment that is going to be able to withstand pressures of anything from 1500 to 5000 psi, specifically engineered to withstand the demands of large scale extraction. Aspects of the equipment such as shell thickness, valves, nuts, and bolts need to be tested and proven to withstand high pressure. Because of the high cost of this equipment, extracts produced by this method are more expensive than other solvent-based extractions.
Although hydrocarbon extractions pull the best terpene and cannabinoid profiles out of the plant, they also present a couple of issues. They are the most flammable solvents—more flammable than ethanol and carbon and require a high pressure (though not as high as CO2) meaning there is a cost to engineer the right equipment. With CO2, pressure rates reach as high 5000psi, whereas with butane and propane pressure rates tend to be between 50-150psi. Typical end-products such as shatter that have a beautiful vivid golden color and a rich terpene smell, live resin, budder, and wax are also concentrate-types used to describe different textures, are all products of hydrocarbon extraction. Using butane and propane, you can make many different types of products.
For extraction on a larger scale, hydrocarbon is very costly and difficult to engineer. It’s not really feasible for large scale hemp extraction, so most extraction facilities process hemp using the CO2 method. This is also why we have seen more facilities move towards ethanol.
From a chemical standpoint, ethanol is a great key to unlock the cannabinoids, but it is an extremely polar solvent. It binds to the cannabinoids and terpenes in the same way hydrocarbons do, but will also bind to undesirable compounds within the plant, like chlorophyll.
In order to bypass this, extractors can chill the ethanol and bypass the undesirable matter, but to chill the ethanol on a larger scale is expensive and requires properly engineered equipment. Factors like mass balance and post-processing procedures need to be considered. It is far more complex than simply pouring ethanol over plant matter, and you need a thorough understanding of how cooling the solving will impact a number of different variables along the process. Due to a lack of regulation, individuals with a lack of understanding of how ethanol interacts with other compounds are extracting cannabis, creating an end-product left with harmful contaminants that can have adverse effects on an individual’s health. Processing at scale with ethanol can be done, but you need a strong team of experts that understand how to navigate these variables.
From a fundamental standpoint of scaled extraction, ethanol is less flammable than hydrocarbons, doesn’t need to be pressurized like CO2 and customers are familiar with ethanol. However, if ethanol extraction is done incorrectly, it can have some of the most damaging health effects due to contaminants.
Ultimately there are no right or wrong ways to extract cannabis, but any extraction process must be properly executed by a team of experts and tested to ensure the end-product is fit to ingest.
Treed CBD is extracted using the C02 supercritical method discussed above, which is why we can confidently claim to have the purest CBD available in the UK today. Have a look at our products and feel free to use the chat box in the bottom right if you have any questions!
Jonathan Machado (Co-Founder)