If you are reading this, you are probably one of the growing number of people that are interested in cannabidiol (CBD). Our blog posts are full of discussions about carrier oils, terpenes and other useful bits of information but until now we haven’t talked about how we actually get CBD out of natural plant material and how this is used to make our oils. What happens in the transition from the hemp plant to a product you can buy from us online?
In the post we will break down the most commonly used extraction methods for obtaining CBD and other cannabinoids from plants and how we turn this CBD into useful products for our customers.
All CBD products (should!!) contain CBD, which is extracted from the hemp plant. Hemp is an industrialised form of cannabis which generally has much lower THC content.
After the CBD is extracted it can then be mixed with various carrier mediums to produce a CBD product including oils as well as capsules and topical creams (which we are currently developing).
If you are already using CBD or follow the industry closer than most you may have already come across various debates regarding the best way to extract CBD from the plant. Best is a loose term and depends on your angle. When extracting CBD there are numerous things to consider – how efficient is the process, how preserved is the CBD structure, does extraction remove any contaminants or introduce any contaminants? Below we breakdown common extraction methods and although we believe our methods are superior, we will take an objective look at all of these techniques.
CBD Extraction Methods
When people talk about how CBD products are made, they’re usually talking about the specific extraction method. The most common methods to extract CBD oil use carbon dioxide, steam distillation, or hydrocarbon or natural solvents.
Carbon Dioxide (CO2) Extraction
CO2 extraction uses something called ‘supercritical carbon dioxide’ to separate the CBD from the plant material. ‘Supercritical’ is a term that describes the state of a substance when it is between two states of matter. In this case, the CO2 has been pressurised to the point that it has properties of both a liquid and a gas, which is why you’ll sometimes see this method referred to as Supercritical Fluid Extraction (SFE).
During the CO2 extraction process, a series of highly pressurised chambers and pumps are used to expose CO2 to high pressure and very low temperatures. This supercritical CO2 is in turn exposed to the hemp plant, resulting in an efficient extraction and production of high quantities of CBD extract. To help visualise the process further we have simplified the main steps below:
- To begin, one chamber will hold pressurised CO2, while a second pressurised chamber holds the hemp plant material.
- The CO2is then pumped from the first chamber into the second. The presence of supercritical CO2 breaks down the hemp, causing the CBD oil to separate from the plant material.
- The CO2and CBD oil are pumped together into a third chamber. The CO2 evaporates, leaving an extract of pure CBD oil behind.
The drawback of CO2 extraction (for manufactures like us, not consumers) is that it requires expensive specialised machinery. CO2 extraction is the preferred method for making CBD products and is considered the gold standard of extraction in the industry – it is the method by which we extract our CBD. Another added bonus is that this method can be tailored to produce specific concentrations of CBD by altering the pressure and CO2 ratios.
CO2 extraction is very safe and extremely efficient and reliable at producing high concentrations of CBD in the resulting oil; according to this study as much as 92%.
If you took O-level/GCSE chemistry than you may have had a run in with a basic steam distillation set up. When using steam distillation extraction methods, hot steam forces 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.
The basic steps are as follows:
- As the water is heated, steam is produced and travels upwards into the plant flask (distillation tank), separating the oil vapours that contain CBD.
- These vapours are then captured in a condensing tube that condenses them into oil and water for collection in another flask.
- Once collected, the oil and water mixture is distilled to extract the CBD oil from the water.
Steam distillation has been around for centuries which means we have had countless years to perfect the technique and we know it works well. However, it is much less efficient than CO2 extraction resulting in large amounts of plant material waste. Therefore, steam distillation is not the technique for those concerned about green credentials. Additionally, due to its set up and slightly in-exact nature, it is much more difficult to produce specific amounts of CBD. Finally, CBD is heat sensitive and if the steam becomes too hot the CBD compound itself can be become damaged due to alterations in chemical structure which may then alter the effects of CBD in the body.
Including Hydrocarbons and Natural Solvents
Solvent extraction is more prevalent among smaller brands or ‘bedroom blenders’ as it is easier to set up and does not have the cost associated with CO2 extraction. It is more efficient than steam distillation and cheaper as well. Despite its simplicity, this method of CBD extraction does have major drawbacks which leads us to suggest avoiding brands who use this method; for your own safety.
Solvent extraction involves a similar process to steam distillation. The major difference is 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 CBD oil behind. Solvent extraction uses either hydrocarbons (e.g. natural gas) or natural solvents (e.g. alcohol).
The hydrocarbons used in this extraction method do give cause for concern as they include naphtha, petroleum, butane and propane. These are not chemicals you would typically associate with a ‘natural’ product and are each toxic in their own way. Now, if these solvents were entirely removed during the extraction process, we would be in the clear but unfortunately, they aren’t. A number of studies have found traces of various hydrocarbon solvents in the final CBD products.
If you do insist on purchasing from a brand that uses solvent extraction, make sure they use natural solvents like ethanol or olive oil to generate their CBD. These solvents are just as effective as the hydrocarbons but are non-toxic but to throw yet another spanner in the works, even if you address the toxic issues, natural solvent extraction can also inadvertently extract chlorophyll which has an unpleasant taste. Generally, natural solvents do not evaporate as well, leaving a lower concentration of CBD behind, as compared to other methods, when the process is complete.
Extraction Comparison Table
At Dr. Ed, we recommend CO2 extraction. Even though we use this extraction method ourselves it is objectively the most efficient and safe extraction method on this list and currently available. Its expense means that in general, the technique is reserved for brands who have invested heavily in the quality of their products. Additionally, while the table labels ‘expensive’ as a downside for CO2 extraction this is a cost absorbed by us not by you, the consumer.
As a rule of thumb, 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 CO2 extraction may be slightly more expensive, but they also tend to be higher-quality products.
To be clear, we don’t wish to bash brands that use other extraction methods. CBD products made using other extraction methods can be safe and high-quality as well, but there can be more risk with these products due to the techniques involved.
Once again lab reports are also very important not just for determining the concentration of cannabinoids in your product but for revealing any potential contaminants as well as the presence of any solvent residue from hydrocarbon extractions.
What Happens Next?
After the CO2 extraction process, the resulting oil is described as ‘full-spectrum’ which means it contains a wide range of cannabinoids including THC. At this point we get to work using a series of steps to entirely remove THC from our products which leaves us with a ‘broad spectrum’ oil. Broad spectrum oils contain a variety of cannabinoids on top of CBD as well as terpenes and other essential oils but no THC. Many of our users prefer broad-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.
Using this broad-spectrum oil as a base we then add our unique terpene blends (derived from a variety of plants) to enhance our oils even further.
This resulting broad spectrum + terpene blend oil is then carefully mixed with our carrier MCT oil to create our stand-out product line.