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The purpose of cannabidiol (CBD) extraction is quite simple – to separate and capture the cannabinoid in a concentrated form suitable for human consumption. The plant utilized, whether it be cannabis or industrial hemp, must be as rich in CBD as possible for quality oil extraction to occur. In this article, we examine five of the most common CBD extraction methods, as well as their unique advantages and disadvantages.
The CO² Extraction Method
This particular extraction technique has three subcategories: supercritical, subcritical, and mid-critical. The most common variation of CO² extraction is supercritical due to its high safety profile and ability to extract a pure and stable product. CO² extraction utilizes pressurized carbon dioxide (CO²) to gently “pull” CBD and other cannabinoids from plant matter (either hemp or cannabis).
CO² Extraction: Advantage
- High safety profile: CO² is widely applied in the food service industry, especially in the production of carbonated beverages.
- Effectiveness: CO² is commonly employed as an extraction solvent in the production of essential oils, as well as in the removal of caffeine from coffee (decaf).
- Purity: Extracted cannabinoids are potent, chlorophyll-free, and pose minimal risk of contamination.
CO² Extraction: Disadvantages
- Expensive: This process uses highly-specialized equipment, with average start-up costs estimated at around $39,000.
- Technical Ability Required: The CO² extraction method should not be attempted by amateur chemists.
The Olive Oil Extraction Method
While ethanol and other liquids are frequently applied in various cannabinoid extraction techniques, olive oil is the most common household substance for at-home extraction practices. Once the plant matter is properly decarboxylated (meaning that the plant’s active compounds have been activated), it is introduced to olive oil and then heated for anywhere from 1-2 hours. This process results in the extraction of cannabinoids, such as CBD.
Olive Oil Extraction: Advantages
- Very Safe: You won’t blow yourself up by utilizing this CBD extraction method. It can be done at home and you don’t need highly-specialized lab equipment.
- Inexpensive: You can set up everything that you need at a low cost. Olive oil is an easy-to-find and inexpensive item that can be picked up at your local grocery store and you likely already have an oven.
Olive Oil Extraction: Disadvantages
- Perishability: The resulting oil is extremely perishable. Store the final product in a cool place away from direct light when not in use to extend its shelf-life.
- Lower Yields: Olive oil extraction produces lower yields – making the possibility of a company utilizing it for mass production non-existent due to the labor-intensiveness of this method.
The Dry Ice Extraction Method
Dry ice extraction is another technique utilized from the comfort of one’s home. This method entails placing finely chopped cannabis or hemp in some sort of container and covering the plant matter with dry ice to freeze the trichomes. A mesh bag is then fitted over the bucket and shaken for about four minutes over plexiglass to remove the frozen trichomes. Finally, a scraper is used to collect the fallen hash, which is then placed into jars for easy storage.
Dry Ice Extraction: Advantages
- Easy to apply: The dry ice method is very simple to understand and easy to replicate at home.
- Clean: Dry ice extraction yields a clean, uncontaminated product.
- Decent yield: This extraction process provides heavy yields compared to other techniques, such as the olive oil method.
Dry Ice Extraction: Disadvantages
- Low-Quality: While dependent upon the preparer, product quality can be ruined if steps are not followed properly.
- Often difficult to get dry ice: Finding several pounds of dry ice can prove difficult in certain areas and online ordering is often expensive to ship.
The Solvent Extraction Method
Butane, ethanol, and other low-grade alcohols are utilized in the solvent extraction method. Ethanol is capable of extracting a broader range of cannabinoids and terpenes, though it also extracts chlorophyll as well, which can potentially cause some pretty unpleasant side-effects. It is possible to remove the chlorophyll by filtering the extract, though this reduces the potency of the oil. The solvent (either ethanol, butane, or alcohol) is added to raw plant material to strip it of its flavor and cannabinoid profile, and will likely even take some of its green coloring as well. Once the cannabinoids are collected in their liquid form, the solution is then heated to evaporate its contents down to its base oil. Butane yields a more potent oil when compared to ethanol, but it is also far more likely to contain irritating solvents that could potentially harm the lungs.
Solvent Extraction: Advantages
- Appropriate for certain products: If using a high-grade alcohol, the resulting product will be high-quality and additionally suitable for vape cartridge production.
- A simple, straightforward process: With proper equipment, the process is not at all difficult to understand and complete.
Solvent Extraction: Disadvantages
- Dangerous: Ethanol and butane are both combustible – making it too dangerous of a process to undergo in one’s home.
- Potentially Harmful: In addition to destroying plant waxes, this extraction process may also produce an oil containing harmful contaminants, such as chlorophyll.
Short Path Distillation Method
Short path distillation is an innovative process that uses molecular separation to separate the individual compounds in cannabis via their specific melting points. The advantage with short path distillation is that you can isolate each specific compound, then combine them together in unique blends that will produce very specific results. The possibilities are endless when you use technology as precise as short path distillation. It is still a fairly new process and there are only a few brands on the market that sell short path distillation equipment. Root Sciences is leading the charge to deliver this new distillation method to the masses. The photo above is of their VKL 70-5 opening model.
Short Path Distillation: Advantages
- No chemical compounds: No butane, ethanol, or pressurized supercritical CO².
- Ability to isolate secondary cannabinoids: As we continue to learn more about the various compounds in cannabis, this method will reign supreme as the demand for cannabinoids other than THC and CBD increases.
Short Path Distillation: Disadvantages
- Expensive: There are very few companies selling short path distillation equipment.
CBD Extraction: Final Thoughts
When searching for a CBD-infused product, it is crucial to know which extraction method was utilized in its making. It would also be beneficial to have a general understanding of the various CBD extraction processes, as each have major impacts upon the quality of the end product (not to mention your health). Supercritical CO² is the method most widely employed by various CBD companies. However, as the industry matures and we continue to learn more about the different compounds in cannabis, short path distillation will likely be the industry standard for larger companies. Consumers who create their own CBD-infused oils though tend to use either the olive oil or dry ice method because they are by far the easiest and most inexpensive. Keep in mind that there are various other extraction methods not discussed in this guide, which may also be worth checking out.