CBD is a natural substance found in cannabis, with particularly high levels in hemp. When a supplement like CBD is discovered, scientists work to figure out how to isolate it and extract it—so as to maximise its effects.
How is CBD extracted? The hemp is put through a high-pressure extraction process using industrial machinery. It is dissolved in a solvent. There are several different solvents used, the most common being carbon dioxide and ethanol (pure alcohol). Both kinds of solvent have their advantages, although ethanol is the more widely used.
Below is Hempura’s guide to how CBD is extracted, step by step. Then we’ll explain exactly what’s in each of our products, and why you should consider them the next time you need to order CBD oil!
The CBD extraction process is long and drawn out, but well-understood. It requires high-quality hemp, tools and specialist equipment you don’t have at home, and know-how. Here’s how it’s done.
The first step in the CBD extraction process is to isolate what you want from the hemp. The only way to safely and consistently remove cannabinoids from hemp is to dissolve it into a solvent. To do so, you need machinery that can put the hemp through both high pressure and high temperature.
There are two different ways to use solvent in this process. You can either use high pressure and high temperature, or high pressure but low temperature. The difference between these two methods is that high temperature may alter the nature of your oil through breaking it down.
This doesn’t mean you have a lower quality oil; but it may mean for the manufacturer that more hemp is required for a certain output of end product.
There are two solvents that are typically used: carbon dioxide and pure alcohol/ethanol. Solvents are typically a kind of liquid, which would normally rule out a gas like carbon dioxide. However, when it’s intensely pressurised, it can act as a solvent. Alcohol is a better solvent than water for things like fats, oil and grease, which is why it’s used to leach CBD oil from hemp.
Solvent extraction gets rid of most of the plant material in the hemp. What’s left behind are cannabinoids such as CBD, THC, and dozens more of chemical compounds. These chemical compounds are what make CBD oil so effective.
Ethanol is an ideal substance for extracting CBD. It’s safer than flammable gas solvents like butane, for a start.
But the best thing about using pure alcohol as a solvent is that it extracts more than just CBD. It extracts a range of cannabinoids, plus plant matter like chlorophyll and terpenes, which are what give cannabis its unique scent.
This means that the end result after ethanol extraction is a full-spectrum oil, which carries the benefits of all cannabinoids and plant material found in hemp. This oil can then be further refined, if desired, to create an oil that’s practically pure CBD.
Decarboxylation is the basic process through which CBD is isolated.
Did you know that CBD isn’t found naturally in cannabis plants? That’s right—instead, what you’ll find in cannabis is the chemical compounds CBDA, also known as cannabidolic acid, or acidic CBD. This chemical compound is inactive, and needs to be activated in order to have an effect on the body. This is done through the decarboxylation process.
Decarboxylation is where you remove a carboxyl group from a molecule through a chemical reaction. Essentially, this means that you take an acid, and turn it into something that isn’t an acid. To do this, you need both heat and time. This is why smoking cannabis or using it in cooking has an effect on the body.
Hemp is decarboxylated at high temperatures, as this is the easiest way to get a consistent result. Temperatures of between 160 and 180 degrees Celsius are required. At lower temperatures, more terpenes are retained; at higher temperatures, more CBDA is converted to CBD, and a purer CBD extract is the result.
It is possible to either decarboxylate the hemp prior to the extraction process, or to decarboxylate the oil after the extraction process. Neither way is substantially different to the other, so this isn’t something you have to worry about.
All of Hempura’s oils are put through the decarboxylation process. This improves the bioavailability of the CBD and other plant compounds found in the oil. In basic terms, decarboxylation makes the CBD oil easier for your body to digest and use.
Winterisation is a purification process that isolates CBD from other cannabinoids. This process ensures that there is no THC left in the oil. It also removes other potentially unwanted elements such as fat or wax. This is what you need to do to manufacture pure CBD isolate.
The process is surprisingly simple. The oil is stirred into 200 proof alcohol until the two are thoroughly mixed. This combination is then placed into a deep freeze. The result is a cloudy solution—this is the sign that it’s ready to be filtered.
Winterisation is only strictly necessary if the oil was extracted using a high temperature, high pressure extraction process. Supercritical extraction draws out lots of material you may not want in your oil. CO2 extracted oils therefore don’t require winterisation, because they were extracted at high pressure, but low temperature.
Most CBD manufacturers use the ethanol extraction process, so most oil you can find is winterised too. Winterisation has no negative effects on the eventual bioavailability or quality of the oil.
Filtering is the step that comes after winterisation. The combination of alcohol and CBD oil is run through a simple filter, e.g. a filter paper and/or a Buchner funnel. This process removes the fats and plant material that you might not want in your finished product.
But there’s still something left to filter out: the alcohol you mixed your oil with. This can be removed easily through the application of heat. The boiling point of alcohol is lower than that of CBD oil, so all that’s needed is to raise the temperature to that point and allow the alcohol to evaporate off.
The evaporating alcohol can be caught and retained. Because it’s pure—as only the alcohol will be evaporating at that particular temperature—you can then reuse the alcohol in the next batch.
Then, you’re left with your pure CBD isolate! This is known as broad spectrum oil, which contains lots of CBD, but only trace amounts of other cannabinoids.
There is an alternative to the winterisation and filtering process. This is known as short path distillation, because it doesn’t take as long.
In short path distillation, all you do is heat the oil. Each of the compounds in the oil has a different boiling point. This means that if you boil the oil at a series of exact temperatures, you can isolate each of the compounds. You can later recombine them, minus the particular things you don’t want, to create your oil.
All you need is a beaker, something to heat it with to an exact temperature, and something to catch the evaporated compounds in. You then heat the mixture at the temperature required to isolate each compound, that you either want or don’t want.
Hempura offer a range of CBD oils—some having gone through the entire extraction and filtration process, and some which have not.
Hempura’s Full-Spectrum Original extracts are essentially a raw CBD oil, which is the direct result of the ethanol extraction process. These oils are dark green to black in appearance, since they still contain the raw chlorophyll and plant material leached from the hemp.
Hempura’s Broad-Spectrum Refined extracts are, as the name suggests, a broad-spectrum of the overall full-plant constituents. These oils go through the winterisation and filtration process to rid the oil of excess plant matter and hemp constituents. Through this purification, a small amount of the organic compounds can be lost to the benefit of taste and purity. After winterisation and filtration, the oil changes from dark green to gold in colour.
Hempura’s supplement capsules are made from decarboxylated 100% ground hemp bud. While decarboxylation does make the CBD inside more readily available to the body, these capsules do contain all the plant matter you find in hemp buds—they’re raw and natural products.
Hempura is a leading company and brand in the CBD oil industry in the UK. Built on a foundation of leading manufacturing techniques, top-grade hemp, high-quality CBD extracts, strong logistics, as well as attention to detail and quality, Hempura has managed to set themselves apart in the UK CBD industry. Hempura's team of experts are always working diligently to ensure you get the best CBD oil, extracts and service every time.