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The popularity of CBD is definitely on the rise, with new people trying out the supplement – and enjoying it! – every day. There are plenty of reasons to do so, the primary driver being that CBD is thought to be a very beneficial health supplement.
When people take CBD, they can do it in a variety of ways. CBD oils remain a very popular option, while capsules, edibles, and even CBD beverages are all catching up. But to make all of these products, the CBD must be obtained from somewhere, right?
Cannabidiol exists within the hemp plant. And unless you are directly eating hemp leaves, then it is certain that the CBD has been extracted from the plant and put into another substance.
If you take CBD often or are thinking about doing so, it’s easy to wonder about the process of creating these fantastic products. So, let’s take a look at all the possible extraction methods for CBD.
Why Does CBD Have to Be Extracted?
Like we said, CBD comes from the leaves and flowers of the hemp plant. As a result, you would have to ingest this plant matter directly in order to consume untreated cannabinoids. This is not only inconvenient and slightly strange, but it would also be very unpleasant! CBD oils taste bad enough – imagine eating hemp leaves!
In order to make the wonderful array of different CBD products, manufacturers must draw out cannabinoids and terpenes whilst leaving the plant matter behind. This hemp extract can then be suspended in oils, cooked into edibles, infused into vape juices, or placed inside capsules. Whatever method is used, the product you consume has undergone some kind of extraction process.
Are Extraction Methods Different for Different CBD Products?
Generally, CBD is extracted in more or less the same way across different products. However, extra steps can be taken depending on the final product that is being made. For example, when producing a CBD isolate, more steps are taken to ensure that the cannabidiol is filtered out from the rest of the compounds.
Another key step in the process could be winterisation. This is the process whereby undesirable compounds are filtered out of the hemp extract. Usually, these refer to plant waxes and lipids, which might be harmful for our health in things like CBD e-liquids. Winterisation works by mixing the extract with 200 proof alcohol and deep freezing it before filtering out these fats. Once this is done, the alcohol is removed using heat to evaporate it.
Apart from this, though, CBD extraction is somewhat the same.
CBD Extraction Methods – The Basics
The first step in CBD extraction is having a cannabidiol-rich plant. Hemp is usually used because it contains very little THC, unlike its psychoactive cousin marijuana. Breeders often grow specifically CBD-rich strains of hemp like Charlotte’s Web, as these are the best for producing CBD products.
Even when special strains are not used, industrial hemp is legal to grow in many countries, including the United Kingdom under special license. Industrial hemp must have less than 0.3% THC by dry weight, which is why it’s perfect for creating 100% legal CBD oils.
So, once you have the hemp, how is the CBD extracted?
1. Olive Oil Extraction
People wanting to make their very own CBD oil on a small scale might use the olive oil method. It is incredibly simple and quite cheap, but obviously it doesn’t retrieve very high yields of CBD.
All you need to do is place the plant matter in a pot of olive oil and heat it at a specific temperature for a certain length of time. However, first you must decarboxylate the plant. This means heating it by itself – essentially baking it in an oven – at a temperature of 120˚C for one hour, or 140˚C for 30 minutes. This activates the natural compounds in the plant, turning Cannabidiolic acid (CBDa) into CBD, and so on.
After, the decarboxylated plant can be placed in olive oil. The heat is turned up to 100˚C for up to 2 hours, and for at least one hour. The cannabinoids are sapped out of the plant and into the olive oil. The result, after the plant matter is removed and the oil is cooled, is a ready-made CBD oil.
However, olive oil is quite perishable and must be stored in a cool, dark place immediately. This, combined with the low yield, makes it uncommon in retail practices.
2. Dry Ice Extraction
Another easy method is dry ice extraction. Once again, it can be performed at home, although it requires more equipment and effort than the olive oil method.
Before dry ice extraction can be performed, the plant matter must be chopped up into small pieces. These pieces are added to a very large bucket and covered with dry ice. As the hemp and dry ice mixture is left for around 3 minutes, the temperature of the dry ice freezes the trichomes – these are tiny growths on the surface of the plant which contain all the cannabinoids.
After the trichomes have been frozen, a mesh bag is placed over the bucket, and the bucket is turned upside down. Mesh with a lower micron number is used at first, meaning that the holes are larger. The upside-down bucket is then shaken, knocking the frozen trichomes off the plant and allowing them to fall through the mesh onto a screen or into another bucket. Then, the process is repeated with different sorts of mesh, this time with smaller holes to ensure that all the trichomes can get through.
This method has a higher yield than olive oil extraction, but it is still not all that cost-effective. Plus, the manual labour means that it’s hit-and-miss as to the quality of the oil. Shaking the bucket for too long, for instance, can ruin the quality of the resulting product.
3. Solvent Extraction
Solvent extraction is a much more common process on a larger scale. It is efficient, fairly high quality, and labelled “Generally Regarded as Safe” by the FDA in America. It can be done with a range of solvents including butane, but generally ethanol is used because it is much safer.
It’s a very easy method to use, because all that needs to be done is place the plant matter into the liquid. The solvent leeches out the cannabinoids, terpenes and other plant matter from the hemp, into the liquid. When this is complete, the mixture is heated to evaporate the alcohol, leaving the hemp extract behind. This extract can then be made into a regular CBD product. As you can see, it’s incredibly simple!
That being said, it is best for this method to be done by a professional. First of all, solvents are highly flammable, and therefore there is a lot of health and safety to take into account. Secondly, it is important to evaporate all of the solvent in order to create a safe final product. When using butane, for example, it can irritate the lungs if any residue remains in the product.
Another thing to note is that solvents will also take other compounds from the plant. It also saps out the chlorophyll from the leaves, for example. Chlorophyll may have some unpleasant side effects if left in the extract, so extra steps must be taken in order to filter this out.
4. Supercritical CO2 Extraction
By far the most common and perhaps superior method for CBD extraction is using supercritical CO2. This method involves a lot of expensive, high-tech equipment that is able to produce high yields.
Carbon dioxide, or CO2, is normally a gas at standard pressure and temperature. However, it can be put into a supercritical state by lowering the temperature to around -56˚C and increasing the pressure to over 75 pounds per square inch (psi). A supercritical state is one in which CO2 can behave like both a liquid and a gas.
While in this state, CO2 can act almost like a solvent, only without the associated dangers of solvent extraction. The supercritical CO2 is passed into an extraction chamber which contains the plant matter. It extracts the cannabinoids, terpenes, and flavonoids from the plant without denaturing or damaging it.
Then, the solution is passed into a separator. The hemp extract goes to a collection chamber, while the CO2 is returned to its original state elsewhere in the system. The CO2 can be recycled over and over, making this a very efficient method.
There are other ways of using CO2 to extract cannabinoids. While supercritical is currently the most common, some manufacturers also use subcritical. This method involves both a low temperature and a low pressure, meaning that it takes longer to extract the compounds. It also doesn’t extract larger molecules like chlorophyll.
This is by far the most popular commercial method of CBD extraction, because not only is it safe, but it also produces a very high-quality end product. There are actually different types of CO2 extraction, including subcritical and supercritical, which we will discuss a little below.
Basically, CO2 extraction involves using pressurised carbon dioxide to pull compounds out of the plant. At certain temperatures and pressures, CO2 behaved quite like a solvent that allows compounds like CBD to be extracted from the plant, with the difference being that CO2 is a lot safer.
Specialised equipment is necessary for this technique, which makes it very expensive. Using this equipment, the CO2 is turned into a liquid by dropping the temperature below -56ºC and increasing the pressure to over 75 pounds per square inch (psi).
When the CO2 has been liquified, the temperature and pressure is increased to the point where the liquid becomes supercritical, meaning that it has some properties of a liquid and some properties of a gas. This means it can fill a container (like gas) while maintaining density (like a liquid). The reason this is done is because it won’t denature or damage the product during chemical extraction.
The supercritical carbon dioxide is passed through high-quality industrial hemp in an extractor, where it pulls out the cannabinoids. The solution is then passed through a separator and broken down into different parts; the supercritical CO2 is condensed back into a liquid to be used again.
In terms of subcritical CO2 extraction, a low temperature and low pressure is used. This is less likely to damage terpenes and therefore retains flavour better, but it takes longer than its supercritical counterpart and it produces a smaller yield. There is also the possibility of mid-critical CO2 extraction, which refers to a happy medium between the two.
Pros of CO2 extraction:
- CO2 is safe for consumption, meaning the resulting products are not contaminated.
- The method is very effective and has a high yield.
- This technique allows for creation of a pure, high-quality product without risk of contaminants such as chlorophyll.
Cons of CO2 extraction:
- This method is expensive due to all the specialised equipment that is needed.
- It also requires some technical ability and should not be carried out by amateurs.
CO2 extraction machinery
In order to complete the extraction process, a closed-loop extraction system is required. This ensures that the CO2 never comes into contact with external elements, ensuring that the system is safe.
Of course, the fact that this machinery is so high-tech means that the process can’t be undertaken by just anyone. In fact, some estimates state that a CO2 extraction kit costs around £30,000. The expensive equipment and the labour costs for a specialised team drives up the price of oils produced through this method.
However, the price is certainly worth it. You are paying for a high-quality oil that, above all, is safe to consume. Remember that some other techniques can actually damage the active compounds in hemp. It also makes much more sense for manufacturers to use this technique as it produces higher yields, allowing them to produce CBD oils on a larger scale.
Which CBD Extraction Method is the Best?
Whichever method is used is completely up to the manufacturer. It is easy to see that CO2 extraction is the most widely used, and this is down to a number of reasons. It is safe, effective, produces high yields, and does not compromise the quality of the final product.
This is not to say that the other methods are terrible, but those producing CBD products on a larger scale would definitely want to opt for CO2 extraction or solvent extraction. Since solvent extraction does have a few associated risks, most manufacturers pay the extra fee to run the high-tech CO2 extraction equipment. It makes consumers feel safer, and it gets the most out of their hemp.
Continue at: https://greenshoppers.co.uk/blog/cbd-extraction/