How is CBD Made From Hemp? The basics covered
A recent publication from a research team at the University of Berkeley, California, managed to bio-engineer yeast to produce cannabinoids such as CBD and THC using only sugar as fuel. In the future, these yeast ‘factories’ may result in much more cost effective and environmentally favourable ways of producing desirable cannabinoids. However, at the moment, we are not quite there yet, and CBD needs to be extracted from industrial hemp before it can be utilised. So first, what is hemp? as a very simple description, it is a strain of Cannabis Sativa that is legal to grow (under licence), this industrial hemp is fast growing and by law must contain a THC content under 0.2%. Industrial hemp is high in CBD, so how do we get the CBD and cannabinoids out that we want without all the impurities? For that various extraction processes are performed followed by differing degrees of purification, dependant on what is the desired use of the end product.
The first step is often performed using solvents, as CBD is a lipophilic (fat soluble) molecule, you’ll need a solvent that cannabinoids is soluble in to extract it from the hemp plant while leaving all the fibrous materials behind. So first let us look at the solvent extraction process to answer the question how is CBD extracted.
How is CBD Made From Hemp – CBD Extraction Processes
Often you will see CBD products with terminology such as ‘CO2 Extracted CBD’ ‘Ethanol extracted CBD’ and so on. Apart from being a marketing ploy does this really mean many thing at all to the consumer?. Unless you have a degree or background in Chemistry or a related field these words really won’t mean much to you. To top it all off there are other terms such as Winterised CBD, CBD distillate, CBD isolate and so on. Most commonly, ethanol or else supercritical CO2 is employed, and this refers to the solvent that was utilised to extract the CBD and other cannabinoids from the hemp. Other solvents can be employed such as butane, and other hydrocarbons but residual solvent in the end product can be an issue with butane.
How is CBD Extracted? – Ethanol CBD extraction
Ethanol is passed over the plant material, in which it solubilises the compounds found in the leaf including cannabinoids and terpenes, while leaving behind the unwanted fibrous materials. However, as ethanol can also solubilise water soluble components it will also take along other components such as chlorophyll, which is why some products that have had little subsequent purification can be green. Ethanol is highly efficient in extracting from hemp and ethanol itself has GRAS status which means it is generally recognised as safe under set PPM limits. Most people drink it after all. More complex industrial systems can control the temperature of ethanol during the extraction process, minimising the quantity of unwanted components. After extraction ethanol is removed from the solid matter and evaporated under reduced pressure to yield the raw CBD oil extract.
How is CBD Extracted? Supercritical CO2 CBD extraction
CO2 extraction is a bit more complex and uses supercritical CO2, normal states of matter which everyone will be aware of is solid, liquid and gas. However, under specific pressured conditions CO2, beyond its critical point and above 31.10 °C, the distinct boundaries of solid and gas no longer exist as the supercritical CO2 can effuse through solids, while still solubilising components like a liquid. One great example of using supercritical CO2 is in the preparation of decaffeinated coffee, where it is used to extract the caffeine from the coffee beans while leaving the bean intact.
After initial extraction, be it using solvents such as ethanol, butane or CO2, you will be left with what is effectively a raw crude oil. If you are involved in the purchase of CBD oil extract you may has seen this and this is generally the cheapest option available from suppliers and would likely have low CBD content mostly of which is CBDa. Products using this would have a very strong grass-like taste, while still containing the full range of terpenes and oils found naturally within the plant.
How is CBD Made From Hemp – Purification Processes
The next step is purification, this is to remove any of the unwanted components such as waxes and fats and other natrual compounds found within the plants, the main terms you will likely have seen are, winterised, distillate and isolates
In the process of winterisation, the crude extract is solubilised in an alcohol, namely ethanol, in which it is cooled to near freezing temperatures, and henceforth the name. As solubility is a variable dependent upon temperature, those components less soluble in ethanol, (like waxes etc) will precipitate out of the solution and can then be filtered off and discarded. A way to think of this in an everyday example is where sugar will collect in the bottom of a cold cup of coffee. After this winterisation process you will be left with CBD oils that will be much higher in CBD content with up to 66% CBD and other cannabinoids. If a product is a product is listed as ‘CO2’ extracted and the oil has been winterised, it is possible to still contain trace amounts of ethanol in the ppm levels, which is totally safe.
Short path distillation
The other method of refinement is known as short path distillation. Going back to our school days, you may remember doing distillation, and this process is pretty much the same. As different compounds have different boiling points, they can be separated through applying heat under reduced pressure. This vapour will then travel through a column which is cooled, causing the vapour to condense and it can then be isolated. This process allows CBD oil to be isolated containing up to 90% CBD content, along with other cannabinoids. One thing to note is that in refinement processes, some, if not all of the terpene profiles will be lost. Many manufacturers will add the specific terpenes back in at the end of the process to the refined oil to achieve a natural terpene profile.
This is CBD with everything else removed, and only pure CBD. CBD isolate is prepared by a process called chromatography. Again, from your school days you may remember doing an experiment where you blotted ink on a piece of paper and placed it in a glass jar with a carrier solution ‘the eluent’. As the eluent (or you can also call this the mobile phase) travels up along the paper, you would have seen the ink separating out into different colours. This effect is due to how different compounds interact with the paper, the more the molecule ‘interacts’ with the stationary phase (the paper), the slower it will rise. Each molecule is slightly different, and you can then see them all separate out. Although that was a very simplistic description, the method for purifying crude CBD oils work much the same. The crude oil will be loaded onto a stationary phase such as silica gel and then an eluent will be fed through the column. As each component will have differing affinities for the stationary phase, the individual components will separate and can then be collected and isolated. As you can see not all CBD products are made the same, using differing qualities of CBD oils from crude extract, winterised, distillates and isolate. If you are ever concerned about the quality of your product, any reputable manufacturer should be more than happy to supply you with a certificate of analysis (COA) upon request, which is a breakdown of different cannabinoid contents of their product. More often than not, in rapidly growing industries people will try and take shortcuts or mislabel inferior products, so it is good to be aware that you are getting the quality product that you are paying for.
I keep seeing the terminology – decarbed and decarboxylated in regards to cannabidiol products, so what on earth does this mean!?. Notably in hemp, cannabinoids don’t exist naturally in the form you will most commonly be aware of such as CBD and THC, in fact they are found as their acidic precursor. In raw hemp you will find Cannabidiolic acid and actually very little cannabinol. This acidic precursor contains a carboxylic acid functional group which can described as COOH, to convert cannabidiolic acid (CBDa) to CBD and requires a process called decarboxylation. In this process the carboxylic acid functional group of CBDa highlighted below in yellow is lost, this reaction is catalysed through the application of high heat and the loss of carbon dioxide to yield CBD.
Conversion of Cannabidiolic Acid (CBDa) to Cannabidiol (CBD) catalysed by heat
How is CBD Made From Hemp
So we hope this article was informative and brought you some new knowledge on how CBD is made from Hemp, or at least helped to clear some things up. This post shows only a brief overview of each process, if you have any more questions on CBD or ideals for articles or any thing CBD related, feel free to contact us and we will be happy to get back to you.