CBD Extraction Methods
In this video Adriaan will tell you about the CBD extraction process and the main methods used in the industry today.
CBD, Cannabidiol is a natural constituant of the hemp plant. Adriaan explains about the 3 most important processes concerning hemp extracts: extraction, decarboxylation and filtration. You’ll find out why supercritical CO2 is not always the best method.
We want to help you make the right choice, if you are looking to find a good CBD wholesaler or supplier and hope this video clears up any questions you may have about CBD oil production and extraction methods.
Differences between the 3 main cbd extraction methods
What are the differences between the 3 most used methods of cbd extraction: supercritical CO2, subcritical CO2 and ethanol extraction?
Supercritical CO2 Extraction
Supercritical CO2 is the most common method used for extracting CBD, mostly because of it’s high yields, fast process and possibility for selectivity.
First of all: what does ‘critical’ stand for?
If carbon dioxide is pressurized above a certain pressure at a certain temperature (the ‘critical’ point), it starts to behave in a special way. It can move though solids like a gas, but it can also dissolve materials like a liquid.
The benefit of this is the speed of the extraction, and the ease of recovering the material that has been extracted. The CBD extract can be separated from the CO2 by simply reducing the pressure.
Another benefit is that by changing the parameters of pressure and temperature, the extractor can be more selective with regards to the exact content of the extract.
A skilled extractor can adjust this process to get the exact output they want, and will have more control over the waxes and fats that end up in the final product. These are often seen as impurities, and it can be expensive to remove them.
So if you are looking to find a CBD supplier, it’s important that they have the right experience.
Subcritical CO2 extraction
Subcritical CO2 extraction has it’s own advantages.
Subcritical means the extraction takes place below the ‘critical’ point, meaning lower pressure or lower temperature, usually both.
This means lower yields, but of a very high quality. There are often almost no waxes in the resulting extract. But, because of this low yield and because the process takes much more time, the resulting extract can be considerably more expensive.
Sometimes, supercritical and subcritical processes are combined to achieve a more complete final product.
Main Benefits of CO2 Extraction
CO2 is generally accepted to be safe because it’s non-toxic and non-combustable. It also doesn’t leave any residual solvents.
There are many solvents that can be used to make herbal extracts. However, from these only ethanol is used in the CBD industry. This is because most other solvents are toxic and explosive. Butane is a good example.
Ethanol is flammable, not explosive, and in small quantities it is safe for human consumption.
Because ethanol is a powerful solvent, it is not that selective, and will produce a full-spectrum extract that also contains fats, waxes, and chlorophyll. This chlorophyll is responsible for the dark-green, almost black color that is often associated with ethanol extracts. It can be avoided by letting the extraction take place at a lower temperature for a limited time. A high grade ethanol extract can have a golden color, and doesn’t need to be green or black.
Letting the material sit in the ethanol for a short time, also called ‘quick wash’, will produce lower yields, but will also reduce the amount of chlorophyll present in the extract. Cooling the extract using low temperature will also reduce the amount of chlorophyll and reduce the green colour.
For small scale productions, ethanol extraction is the go-to method because the equipment is relatively inexpensive, and in the hands of a skilled chemist, the resulting extract can be top shelf. In my opinion, it doesn’t deserve it’s bad reputation. For sublingual, encapsulated or topical applications, ethanol extracts are perfectly suitable.
Decarboxylation – turning CBDA into CBD
The next process is decarboxylation.
In the dried flower, CBD is present in it’s acidic variant, Cannabidiolic acid or CBDa. This has it’s own unique properties that have to be studied more. CBDa can be turned into CBD by mild heating, a process called decarboxylation. The resulting extract is often labelled Decarb, while the unheated extract is called RAW. CBD is more well known than CBDa, as most of the medical studies today have been done using CBD.
Filtration – Winterization
The final process we will talk about is filtration.
CBD extracts can be filtered in various ways, depending on the specific application or product you need. The most important is winterisation. This is a common process in the production of vegetable oils, and is used to filter out certain fats and waxes. The extract is diluted in alcohol, and then slowly cooled to cryogenic temperatures (cryogenic meaning very cold). When this happens, the waxes in the solution coagulate (they become solid), and can then be filtered out. This normally happens with help of a vacuum to pull the solution through a filter, as it gets very thick at low temperatures. The alcohol is then distilled, normally using a rotavapor. This is a machine that turns the solution in a warm bath, distilling the alchohol and leaving behind a beautiful and wax-free CBD extract, sometimes referred to as golden oil.
Winterised CBD extract is important for Vape applications
If you are looking to buy CBD extract for vaping applications, it’s very important to make sure it has been properly winterized. If not, the remaining fats and waxes get stuck in the coil of an electronic cigaret, where they burn and form all kinds of unwanted chemicals. When using a ceramic coil, they stay behind and create a sticky mess. Unfortunately, there are still a lot of vape products on the market that have not been properly winterised. You can recognise them by their distinctive burnt flavour, and the way they irritate the throat. A good vape extract, vaporized at the right temperature, between 180 and 195 degrees celsius, should be smooth.
- Supercritical CO2 is a high-yield, selective, fast and economical extraction method.
- Subcritical CO2 produces a lower yield, but doesn’t require winterisation for some applications.
- Ethanol extractions are full spectrum, and also contain fats, waxes and sometimes chlorofyl.
- Decarboxylation means turning CBDa into CBD.
- Winterisation is a filtration process that removes the unwanted fats and waxes.
Work together with us
I’ve worked in this industry since 2014, and I know all the big players in Europe. I directly represent several of them, and can also introduce you to the smaller producers, that you will have a hard time finding on google right now.
If you want to talk more about wholesale CBD, please reach out and contact us