CBD (Cannabidiol) oil extracted from hemp plant has been touted for treatment of epilepsy, anxiety, insomnia and chronic pain. Many scientific studies demonstrate its effectiveness. As per World Health Organization, “In humans, CBD exhibits no dependence or abuse potential”. Human Body naturally produces cannabinoids which helps vital bodily functions.
It’s no wonder that interest in CBD oil has picked since 2018 farm bill, as hemp is no longer considered as controlled substance, CBD oil is considered legal if it contains less than 0.3% of tetrahydrocannabinol (THC). THC is psychoactive constituent of cannabis which causes dependence in humans.
First step in production of CBD oil requires converting hemp plant material into crude extract. Process of producing crude extract involves passing of solvent through plant material. Hemp plant contains compounds like cannabinoids, terpenes, chlorophyll etc. When solvent is passed through plant material, these plant ingredients gets dissolved in solvent and then this mixture is collected as crude extract which requires further processing before high quality oil is produced.
The following methods are widely used for CBD oil production. We will discuss pro and cons of them in detail.
- CO2 extraction method:
It is a fantastic method for producing high quality CBD oil. When CO2 is pressurized while maintaining its temperature, gas gets converted into liquid form which is then used as solvent. This solvent is passed through plant material to produce crude extract. Efficiency of this process is almost 90% and quality of CBD oil produced is far superior compared to other methods.
This method requires expensive machinery along with skilled manpower. Hence produced oil is comparatively expensive.
- Ethanol extraction:
This method is less expensive compared to CO2 extraction but maintaining high product quality is still possible with professional expertise and meticulous post processing of crude extract. They produce high quality CBD oil with ethanol extraction method at lowest possible cost.
This method uses ethanol as solvent, as per FDA ethanol has a low risk of acute or chronic toxicity when residue is less than 0.5% of finished product.
Ethanol is soluble in water similarly chlorophyll in hemp plant is also soluble in water. So Chlorophyll gets dissolved in ethanol, which results into bitter and grassy crude extract. Filtration is required to remove chlorophyll but it can also remove desirable cannabinoids resulting in lower quality CBD oil.
It’s very important to have experienced operator while conducting this extraction. That’s why above example is very important which illustrates with expertise in production, high quality CBD oil similar to produced in CO2 extraction can be obtained at much less cost by using this method.
- Lipid Extraction:
This method uses lipids or fats as solvent. Lipids have capacity to absorb hemp plant compounds. This method is not commonly used. Organic coconut oil can be used as solvent. It leaves no toxic residue in CBD oil which is the main benefit of this method.
- Hydrocarbon extraction:
This method uses hydrocarbons like butane, propane, hexane or pentane as solvent. These solvents have low boiling point, so when crude extract is produced, removing solvent becomes very easy due to at low temperature hydrocarbon solvent gets evaporated. This method was used in early days.
Even though this method is cheap and easy, it faces some serious drawbacks as CBD oil produced via this process contains low concentration of desirable cannabinoids and high concentration of illegal THC along with unsafe residue which can be dangerous for human immune system. It’s strictly recommended to avoid using this method for production of CBD oil.
- Post processing:
Crude extract contains many unwanted hemp plant compounds like chlorophyll, terpenoids and fatty acids. Removal of these compounds is necessary to produce high quality CBD oil.
- Winterization purification:
In this method, crude extract is mixed with 200 proof alcohol, this mixture is then kept in freezer for 12 hours. Then filtration is carried out by using paper filter. Unwanted compounds are removed via this filtration.
Alcohol have low boiling point than CBD oil, so end product is warmed until alcohol gets evaporated.
Hemp plant contains cannabinoids in acid from like CBDA (Cannabidiolic acid). We need to activate CBDA by converting it into CBD. Decarboxylation process involves CBDA conversion to CBD by simply heating the crude extract.
- Unwanted compound removal:
CBD oil produced after winterization and decarboxylation can be directly used in end products for consumers. Processes like distillation and chromatography often performed for isolating pure form of cannabinoids from remaining terpenes.
CBD isolate produced after distillation contains 99% of cannabinoids, its white powder having no odour or flavour.
- Best CBD extraction method?
It depends on cost benefit analysis and final spectrum of CBD oil extract required, while CO2 extraction gives higher quality, ethanol extraction can be cost effective while maintaining same quality is possible with use of expertise and efficient post processing practices.