CBD Extraction Methods Decoded
CBD or Cannabidiol is a naturally occurring compound found in cannabis. A safe, non-addictive substance, CBD is one of more than a hundred “phytocannabinoids” which are unique to cannabis and endow the plant with its robust therapeutic profile (1).
Ok, CBD is a phytocannabinoid, but how is this compound obtained from cannabis?
All CBD containing products contain oil rich in CBD. This oil, sometimes referred to as PCR Hemp Oil (PhytoCannabinoid Rich) is obtained by “extracting” the CBD from the hemp plant. Extract (extracted, extracting, extracts) as defined by Webster’s Dictionary, is a verb meaning:
a: to withdraw (something, such as a juice or a constituent element) by physical or chemical process, (2).
This is why you’ll often see “hemp extract” on the product label and in the ingredients list. Once the extraction has occurred, the oil is ready to be added to a multitude of products, including CBD Oils, Tinctures, Topicals, Edibles, Capsules, Beauty products and more.
3 Types of CBD Extraction Methods
- CO2 (Carbon Dioxide) Extraction
- Steam Distillation
- Solvents (Natural and Hydrocarbon)
Carbon Dioxide (CO2) Extraction
CO extraction uses supercritical carbon dioxide to separate the CBD oil from the plant material. “Supercritical” refers to the CO containing properties of both a liquid and a gas state, which is why you’ll sometimes see this method referred to as Supercritical Fluid Extraction (SFE).
During CO extraction, a series of pressurized chambers and pumps are used to expose CO to high pressure and very low temperatures, resulting in an extracted oil containing high amounts of CBD.
- At the start of extraction, one chamber will hold pressurized CO2 , while a second pressurized chamber holds the hemp plant.
- The CO2 is then pumped from the first chamber into the second. The presence of supercritical CO2 breaks down the hemp also in the chamber, causing the oil to separate from the plant material.
- Finally, the CO2 and oil are pumped together into a third chamber. The gas evaporates, leaving an extract of pure CBD oil behind.
While it requires expensive specialized machinery, CO extraction is the preferred method for making CBD products. It’s extremely safe and efficient at producing high concentrations of CBD in the resulting oil—as much as 92% according to one analysis.
The precise nature of CO2 extraction also makes it suitable for producing specific concentrations of CBD oil. Manufacturers can simply adjust the solvent and pressure ratios to achieve the desired concentration of CBD.
The CO2 extraction process is also widely used to create many other products besides CBD oil, such as decaffeinating coffee or tea, or extracting essential oils for use in perfumes.
With steam distillation, steam causes the CBD oil to separate from the hemp plant. The hemp plant is contained in a glass flask, with an inlet and an outlet. The inlet connects to another glass container, beneath the plant flask, that contains water that is set to boil. The outlet connects to a condenser tube.
- As the water heats up, the steam travels upwards into the plant flask, separating the oil vapors that contain CBD.
- These vapors are then captured in a tube that condenses them into oil and water.
- Once collected, the oil and water mixture is distilled to extract the CBD oil from the water.
The steam distillation technique is tried and true, having been used to extract essential oil for centuries, but it’s less preferred than CO extraction due to its inefficiency. Steam distillation requires significantly larger amounts of hemp plant, and it’s more difficult to extract exact amounts of CBD concentration using this method.
There’s also an element of risk with this method. If the steam gets too hot, it can damage the extract and alter the chemical properties of the cannabinoids it contains.
Solvent Extraction (Hydrocarbons and Natural Solvents)
Solvent extraction follows a similar process to steam distillation, except that it uses a solvent rather than water to separate the CBD oil from the plant material. This creates a resulting mixture of the CBD oil with the solvent. The solvent then evaporates, leaving pure CBD oil behind. Solvent extraction uses either hydrocarbons or natural solvents.
Solvent extraction is more efficient than steam distillation, and it’s also less expensive. However, the solvents used in hydrocarbon extraction (including naphtha, petroleum, butane, or propane) create cause for concern. The solvent residue can be toxic and increase one’s cancer risk if they aren’t fully eliminated during the evaporation step—which doesn’t always happen. Some studies have found traces of petroleum or naphtha hydrocarbons residue in CBD products that used solvent extraction.
To avoid the risk of toxic residue, solvent extraction can use natural solvents instead, such as olive oil or ethanol. These solvents are just as effective at extracting CBD oil, but remove the risk of toxic residue.
However, natural solvent extraction is not without its downsides. When natural solvents like ethanol are used, chlorophyll may also be extracted. This gives the resulting oil an unpleasant taste. If the CBD is used in capsules or topicals, this isn’t a big deal, but many CBD products are eaten or inhaled (such as gummies, tinctures, vape oils), so this can make them harder to sell.
The larger problem with natural solvents, though, is that they don’t evaporate very well. As a result, the CBD extract contains a lower concentration of CBD than it would with other methods.
What Is the Best Extraction Method for CBD Oil?
There are pros and cons to each extraction method. At CBDOil.org, we recommend CO extraction. While it is the most expensive extraction method, it consistently produces the highest concentration of CBD, resulting in a quality product. It’s also one of the safest extraction methods, leaving behind no neurotoxic residue.
When purchasing CBD products, find out which extraction method the company uses, as this can be an indicator of the quality and value of their products. Products that use CO extraction may be more expensive, but they also tend to be higher-quality.
CBD products made using other extraction methods can be safe and high-quality as well, but there can be more risk with these products. Specifically, CBD products that were made using hydrocarbon extraction may contain solvent residuals. And while steam distillation and natural solvent extraction are lower-risk, they can produce lower or inconsistent amounts of CBD, which can affect the cost/mg value of your CBD product.
Beyond their extraction method, also confirm that the company uses a third-party lab to test the concentration of the CBD in their products, as well as the safety of the other ingredients. Any reputable manufacturer will make these test results readily available on their website, with their product packaging, or upon request. The test results will show the potency of the CBD and other cannabinoids (described in milligrams). They’ll also reveal any potential contaminants, as well as the presence of any solvent residue, if the product used hydrocarbon solvent extraction.
What Happens After Extraction?
After extraction, the resulting CBD oil is described as “full-spectrum”. This means that other cannabinoids besides CBD, including CBDA, CBDV, THC, and others, are still present. As long as the product is sourced from hemp, the amount of THC will be 0.3% or less (which makes it legal anywhere in the U.S.).
Full-spectrum CBD oils also contain other beneficial elements from the plant material, such as terpenes and amino acids. Many people prefer full-spectrum CBD oil because of the “entourage effect”. While this effect has not been proven, some users believe that the CBD is able to engage the endocannabinoid system more effectively when more cannabinoids are present.
However, some people would rather have no THC in their oil, even in very low, legal amounts. These people prefer CBD isolates. To create CBD isolate, the extract is cooled and further purified into crystalline isolate form. This results in a white, flavorless powder. Because it contains only CBD, CBD isolate is less expensive per milligram, contains no THC, and has no flavor or odor.
Finally, regardless of whether it is turned into a CBD isolate or remains full-spectrum, the CBD oil is added to other substances to create various CBD products, (3).