Cannabidiol (CBD) is a cannabinoid that is gaining importance in the world of cannabis and numerous fields for its medicinal potential. A ton of benefits from this phytocannabinoid have been identified, including its anti-inflammatory, neuroprotective, antioxidant, and anticonvulsant action, just to name a few. Not only does CBD offer these impressive effects, but it is also non-intoxicating, making it a healthier choice for a large group of people. All of these properties and effects were brought to light thanks to the discovery of endogenous cannabinoids within our bodies, which activate and regulate our Endocannabinoid System.
A huge market is emerging around this cannabinoid. Today there are many products, including foods and supplements, that make it easy for consumers to include CBD in their daily lives. This booming market and the accompanying innovation has led to new and refined extraction methods that are used to isolate and take advantage of cannabinoids such as CBD, terpenes, and a large number of other components present in the cannabis plant.
How is CBD extracted?
There are several extraction methods to obtain cannabidiol from cannabis. CBD is present in the plant as an inactive ingredient, cannabidiolic acid (CBDA). The conversion of CBDA to active CBD, from a pharmacological point of view, is called decarboxylation. In this process, a molecule of carbon dioxide is separated from CBDA by heating it or by enzymatic catalysis. This process is similar to the decarboxylation of THCA to THC, a process that consists in burning THCA to release the psychoactive substance THC.
When consumers search for CBD products, they typically discover that it comes in two main forms, CBD isolate and full spectrum extracts. Although a CBD isolate offers higher levels of CBD, full-spectrum extracts contain many other benefits that work synergistically with cannabidiol.
Before explaining the different extraction methods that exist, we have to be clear about one thing: if we want to obtain a good CBD extract, it will be necessary to have a cannabis plant that is rich in CBD. We should also remember that the two main components of Cannabis Sativa are THC and CBD, which are found in different proportions depending on the variety of the plant.
Furthermore, cannabinoids can also be created synthetically in a laboratory. However, since its production is completely different from CBD extracted from plants, in this article we will focus only on natural CBD extracts.
Once this point is clarified, the next question that may come to mind is: why do we need to extract CBD? Or, in other words, can’t we benefit from these cannabinoids directly from the plant? Well, the answer is an absolute “no”. At least not if we seek to obtain a pure, effective, concentrated product suitable for therapeutic use.
In fact, thanks to the extraction of CBD, what we achieve precisely is the separation of those cannabinoids that interest us to create a concentrated form of them, which will then be the one we normally use for consumption. In addition, in this way we will make sure to have a product without THC (or, at least, with a minimum percentage that in no case will have psychotropic or negative effects on our health).
However, not all extraction methods are the same, both in terms of the quality of the final product and its safety for consumption.
If you want to know how these methods differ, you may want to keep reading.
Carbon dioxide (CO2) extraction
CO2 extraction uses supercritical carbon dioxide to separate CBD from the cannabis plant. When we use the word “supercritical”, we are referring to the properties that allow the CO2 molecules transit between a liquid and a gaseous state, which is why this method is sometimes called supercritical fluid extraction (SFE). A variant of this extraction method is known as “subcritical extraction“, which consists in a very similar process, being the main difference the usage of a lower temperature and pressure to obtain the CBD extract.
Today, the CO2 extraction method is considered the safest way to obtain CBD, in addition to being the one which gives us one of the purest forms of CBD and whose process is more controlled. In fact, unlike the extraction of CBD with oil, the extraction of CBD with CO2 implies having the adequate machinery, as well as certain technical knowledge. So, it is safe to say that this is one of the most expensive and complicated methods to obtain CBD.
In this case, the cannabinoids are obtained after a process in which different temperatures and pressures are applied to the cannabis plant, which will be measured and adjusted depending on the final characteristics that we want to obtain in our oil.
In this way, and by means of a closed circuit butane hash oil extractor, best known as BHO extractor (a specialized machine divided into three chambers), we will use CO2 as a solvent gas. This will go from the first to the second chamber, where we will obtain the supercritical form of this gas that will be in charge of extracting the cannabinoids from the cannabis plant.
Finally, both the supercritical CO2 and the cannabinoids will pass to the third chamber where both compounds will be separated again, leaving the gas at the top and the oil at the bottom, and it will be precisely that oil the one we will use for our CBD products.
While this technique requires specialized (and usually very expensive) machinery, it is the preferred method for making CBD products, since it is highly safe and efficient in producing high concentrations of cannabidiol in the resulting oil, up to 92% based on an analysis. The precision of the CO2 extraction method also makes it very suitable for producing specific concentrations of CBD oil. Manufacturers can simply adjust the CO2 pressure to achieve the desired concentration of CBD.
The CO2 extraction process is also used to create many other products besides CBD oil, such as decaffeinated coffee or tea, or the extraction of essential oils for use in perfumes.
With this technique, the vapor is what causes the CBD oil to separate from the cannabis plant, which is in a glass flask that usually has a spherical shape with a straight and narrow neck, and an inlet and an outlet. The inlet is connected to another glass container, below the flask with the cannabis plant, which contains boiling water. The outlet is connected to a condenser tube.
As the water heats up, the steam rises into the plant’s flask, separating the oils that contain CBD. These vapors are captured in a tube that condenses them into oil and water. Once collected, the mixture is distilled to separate the CBD oil from the water.
The steam distillation method has been used for centuries to extract essential oils used in perfumery, but is used less in the cannabis industry due to its inefficiency. Steam distillation requires larger amounts of plant material, making it more difficult to extract precise amounts of CBD. There is also a fundamental element of risk: if the steam gets too hot, it can damage the extract and alter the chemical properties of the cannabinoids it contains.
Solvent extraction (hydrocarbons)
This extraction method follows a process similar to steam distillation, except that it uses a solvent instead of water to separate the CBD oil from the plant material. This creates a mixture of the CBD oil with the solvent, which then evaporates, leaving us with the CBD oil. As it is an extraction method that uses chemical solvents (mainly ethanol, butane or alcohol), it is relatively easy for the final product to have toxic residues. Therefore, these CBD extracts will not be suitable for therapeutic use.
Alcohol has been used in traditional medicine systems for centuries, possibly millennia, to extract chemical compounds from plants for the purpose of making tinctures. What makes a solvent extract unique is that the solvent evaporates after we extrac the molecules we need. This process has become more popular recently because of Rick Simpson, who advocated this method as a homemade way of making cannabis oil.
Butane is usually recommended because it gives good results and high yields, but there are many different classes and obtaining a good quality gas is often difficult (apart from being dangerous). Furthermore, absolute ethanol is very effective due to its purity, because it will drag the components we do not want, such as chlorophyll, (which represents a big proportion of the weight of the dry cannabis plant) and because it is much more manageable.
In addition, despite being an extraction method that we could consider cheap and easy to perform, it is the one that comes with the greatest risks. We must not forget that the chemical solvents used in this type of extraction are highly flammable. Therefore, the possibility of an accident occurring during its performance is very high.
On the other hand, these chemical solvents destroy the waxes that can be found on the cannabis plant, which have beneficial health properties. Also, contrary to other methods, it also extracts chlorophyll along with cannabinoids, which can add a bitter taste to the final oil.
As for the method itself, it is simple: when the solvent is mixed with the plant, the cannabinoids from the plant pass into the liquid we have used. Later, this liquid will be heated until it evaporates, giving us a concentrated oil.
Solvent extraction is more efficient than steam distillation and is also less expensive. However, there are concerns about substances used in hydrocarbon extraction (including petroleum, butane, or propane). The residue they leave behind can be toxic and increase the risk of developing cancer if not completely removed during the evaporation phase, which is not always the case. Some studies have found traces of hydrocarbon residues in CBD products that use this type of extraction.
To avoid these risks, it is recommended to use natural solvents, such as ethanol, which is just as effective, but leaves less trace of toxic residues. However, this variant is not without its drawbacks. For example, just as said before, when ethanol is used, chlorophyll can also be extracted, which gives the oil an unpleasant taste. So, if CBD is used in capsules or topical creams, nothing happens, but many CBD products are eaten or inhaled (such as gummies, tinctures, oils…), so this can make it a little difficult to sell certain products.
Extraction of CBD with oil
Without a doubt, this is one of the most traditional methods of extracting CBD and also one of the safest, besides being a cheap and relatively easy way to do it. Products like hemp seed oil, olive oil, and coconut oil are quite effective at extracting cannabinoids from the cannabis plant because its compounds are lipophilic, meaning they are well absorbed by fat.
This is an extraction method oftenly used by some beginners because it is easy and natural. There is no risk of having harmful residues in the final product, and healthy vegetable oils undoubtedly add nutrients like omega fatty acids to the mix. With this extraction method we will need to use a vegetable oil (generally olive, hemp or sesame oil) that will be mixed with the decarboxylated cannabis plant; this will allow us to “activate” the cannabinoids.
We will heat this mixture again to extract the cannabinoids, which will pass into the oil that we have used. This oil will then be suitable for consumption or topical application. In addition to being easy and safe to consume, one of the advantages of this method is that no chemical residue will remain after its extraction.
However, the useful life of this extract will be shorter than the extracts obtained with other methods, since it is mixed with an oil (which will also influence its conservation). And since the oil will not evaporate when heated, the CBD extract will contain a lower concentration of CBD in comparison to the concentration of CBD obtained in other extraction methods.
An additional consideration
After having seen the most common extraction methods, we should consider something that will also influence this process: which parts of the cannabis plant do we have to use to extract CBD?
Currently, there is no general opinion. While some people tend to use all parts of the plant for CBD extraction, others prefer to use the flowers, stems and leaves. Generally, in the production of CBD oils that are used therapeutically, manufacturers resort to the extraction of cannabinoids from the whole plant. In this way, it is believed that greater benefits are obtained by achieving a broader spectrum of active compounds in the final product.
How is CBD purified?
Once we know the different extraction methods, it is necessary to briefly talk about the purification of CBD. Above all, we should take into account that not all extracts will have the same purity. In fact, two independent processes, CBD extraction and CBD purification, go hand in hand and will always be closely related.
As we have already mentioned, the CBD extracts obtained by means of supercritical extraction with CO2 are those that provide us with the purest product, which also has a neutral flavor and aroma, in addition to being the ones with the greatest therapeutic properties. However, it is necessary to apply heat to obtain them, which could lead us to think that some of their compounds deteriorate.
On the other hand, when it comes to purity, CBD extracts with oil also give us a high-quality product. In this case, the only downside would be the lower concentration of CBD. However, the use of vegetable oils of great nutritional value such as olive oil, adds a plus to this type of product.
As for the extracts obtained based on solvents, their purity remains in between. Especially since we cannot guarantee that the final product is free of toxins.
All CBD extraction methods share a common element: the (almost) zero presence of THC. In fact, it is common to see this indication in CBD supplements, foods and creams. Therefore, we can be sure that we will not be acquiring a psychotropic product, but a therapeutic one.
What Happens After the Extraction?
After the extraction, the CBD oil obtained is described as “full spectrum”. This means that other cannabinoids are still present, in addition to CBD, (including CBDV, THC, and others). As long as the product comes from industrial hemp, the amount of THC will be 0.3% or less (which makes it legal in many countries).
Full spectrum CBD oils also contain other beneficial elements from the cannabis plant, such as terpenes, amino acids, cannabigerol, cannabinol, among others. You will be surprised to know that, in addition to all the nutritional contents mentioned above, there are 20 amino acids in the entire spectrum of CBD oil and 9 of them are essential amino acids.
All the important essential fatty acids, such as Omega 3 and Omega 6, are available in full spectrum CBD oil. The best thing about these fatty acids is that they are good for our cardiovascular health. The ratio of those acids in CBD oil is 3:1, which means that CBD oil produces a decent amount of essential proteins. Many consumers prefer oil CBD full spectrum since CBD can interact with the endocannabinoid system more effectively when more cannabinoids are present.
However, some users prefer that there is no trace of THC, even in very low legal amounts. These users usually prefer CBD isolate extracts, in which the extract is cooled and further purified as a crystalline concentrate. This results in a flavourless white powder or crystals. And because it contains only CBD, CBD concentrates cost less per milligram, contain no THC, and are odorless, removing terpenes from the equation. CBD isolate is fundamentally CBD in its purest form. However, CBD isolate is oftenly mixed with oils that are used for pain relief and diseases such as cancer, schizophrenia, and even multiple sclerosis.
Regardless of whether it becomes a concentrate or remains full-spectrum, CBD oil is added to other substances to create the CBD products that are conquering the cannabis market.
What is the best method of extraction?
This question depends on many factors, and it depends on what materials we have access to when we decide to make CBD extracts. However, as a consumer, CO₂ extraction appears to be the best option and produces premium quality CBD products. The ability of this method to extract active components without leaving any harmful residue is unmatched. This method creates a clean and safe full spectrum oil rich in CBD and beneficial terpenes.
Uses of CBD extracts
The uses that we can give to CBD extracts are multiple and, as we said at the beginning of the article, they are increasing. From supplements of all kinds (pills, tinctures, dragees, etc.) to edibles and cosmetics. Even special CBD-based products for animals, which can also benefit from the therapeutic uses of cannabidiol. With CBD oil we can take advantage of the therapeutic benefits of cannabis without suffering the side effects caused by smoking. It is one of the most effective options when it comes to consuming cannabis therapeutically.
According to a study published in the journal Pharmacology & Pharmacy, CBD-rich cannabis plant extract has better efficiency than CBD used in its pure chemical form. This is due to the presence of other cannabinoids and molecules in the plant, which act as an enhancer of its properties. Among the extense amount of uses it can be given, some of these could be: reducing the pain caused by arthritis, alleviating the symptoms of chemotherapy, fighting the seizures of epilepsy, protecting against neuronal degeneration in Alzheimer’s disease, stopping the progression of amyotrophic lateral sclerosis (ALS), helping with depression and anxiety, and many more.
Finally, we must be clear that not all products are the same. And that its effectiveness, purity, price and quality will depend on many factors; among them, the way to extract the CBD as we have already explained, as well as the rest of the ingredients that they include in their composition, and the way of consuming them, which will also be an influence when choosing any of these products.
Read More June 20, 2021