CBD extraction methods
At Royal Organics we extract our CBD extracts from organically grown, superior genetic hemp plants, which have a high CBD content. There are several processes for extracting CBD from hemp, but not all of them are safe. Royal Organics uses the Supercritical CO extraction method 2which is recognised as the cleanest and safest way to produce CBD extracts completely free of any residual compounds.
CBD and its many health benefits are a hot topic as scientific studies supporting it are becoming more and more abundant. Although the vast majority of articles talk about the uses and benefits of CBD, most people have questions about how CBD oil is produced.
Hemp cultivation and harvesting
The process begins with a cultivation of the hemp plant. The hemp seeds are carefully selected by choosing varieties with the highest natural abundance of CBD and reduced THC content. These seeds are then sown and the hemp plants grow for 120 days.
When the flowering period comes to an end, the plants are harvested by cutting close to the root. The seeds and leaves are removed and the stems are left to dry. The stems are moistened to soften the fibre in a process known as ‘shrinking’. This is followed by ‘decortication’, where the fibre is separated from the stem by hand for further processing.
Main CBD extraction methods
There are three main methods of extracting CBD from the hemp plant:
- Food grade oil
- Liquid solvents
- CO₂ Supercritical.
Liquid solvent extraction is the most widespread industrial method. However, at Royal Organics we use the Supercritical CO₂ extraction method for reasons of quality and precision.
Extraction with food grade oil
Using oils for CBD extraction is one of the simplest and most popular methods among home growers. The process starts by applying heat to decarboxylate the raw plant material to activate the cannabinoids, such as CBD. Olive oil, for example, is then added, heating the mixture to 100°C for a total of 1 to 2 hours. This causes the olive oil to gradually evaporate. When the oil has completely evaporated, only a highly concentrated CBD oil remains.
This method is very economical, simple and safe to perform. It does not require special equipment, making it accessible to those who perform non-professional home extractions.
This extraction method produces very little end product. In addition, the resulting oil is highly perishable. It should be stored in a cool, dry place and used at very short notice so that it does not deteriorate.
Liquid solvent extraction
Liquid solvent extraction is usually performed with ethanol, propane or butane. The plant material is mixed with one of these solvents and boiled to extract the desired compounds. The solution is then filtered and the remaining solvent is removed by heat or vacuum, leaving a CBD-rich concentrate.
The equipment needed for liquid solvent extraction is not overly complicated or specialised. Moreover, it produces a highly concentrated oil considering the simplicity of the process.
This method requires much more energy than the other methods. It is also not as precise as the CO₂ extraction process as it is not able to select which compounds are to be extracted, resulting in lower quality products. Working with powerful solvents at high temperatures is highly hazardous and poses potential risks to the environment. If the process is not carried out in a strictly rigorous and correct manner, there is a great potential risk that the final product will contain traces of the solvent used.
This is the extraction method we use at Royal Organics because it produces the best quality oil. Supercritical CO₂ extraction is a very popular method in other sectors, such as cosmetics and pharmaceuticals.
At its “critical” pressure and temperature, CO₂ acquires a state between liquid and gas, which makes it possess the characteristics of both states. Supercritical CO₂ extraction uses CO₂ as a “green solvent” to extract CBD. The CO₂ must reach the optimal pressure and temperature for extraction to occur. This requires a lot of precision and in-depth, specialised knowledge as each compound is isolated at a different temperature.
In industrial CO₂ extraction systems, there are three main components: the extraction vessel, the accumulator and the separator. The extraction vessel is filled with plant material and the accumulator pumps liquid CO₂ into the vessel. This initial process creates a mixture of CO₂ and cannabinoids. The mixture then passes into the separator where the CO₂ is removed and the CBD extract is isolated.
CO₂ extraction is a safe method for both people and the environment. It does not require any toxic chemicals and also employs a closed loop system that is able to recycle the CO₂ for later reuse. CO₂ extraction works at lower temperatures than liquid solvent extraction so the terpenes from the hemp plant are better preserved. This results in an oil of the highest quality.
This method is very expensive as it requires very specialised equipment. It is essential to have an experienced professional chemist as this process requires in-depth specialised knowledge. For these reasons CO₂ extraction is not suitable for non-professional home extraction.
All three of the above extraction methods are capable of producing unpurified CBD oil of decent quality and many companies market it as such. Unpurified or “crude” CBD oil is quite dark in colour and can have an inconsistent concentration and a strong odour. However, there are additional processes to obtain a truly excellent quality end product.
At Royal Organics, we purify our CBD oil using a specialised filtration system. This process removes unwanted fats and chlorophyll. The purified oil is lighter in colour, has a mild, natural aroma, high potency and a liquid consistency.