Top 3 CBD Extraction Methods Explained
CBD extraction is both an art and a science. While there are clear data indicating certain extraction methods are better than others, extraction savants endlessly debate the benefits and detractors of each method used to remove CBD and other substances from cannabis.
Depending on the extraction method you choose, lab tests for your extracts might look better or worse. In a worst-case scenario, you might even test positive for residual solvents.
Learn which CBD extraction methods deliver the best results, and find out how the top three extraction methods compare. Then, discover answers to the most important cannabis extraction questions.
What is the best CBD extraction method?
The best three cannabis extraction methods, listed in order of desirability, are:
- CO2 extraction
- Ethanol extraction
- Solventless extraction
We’ll provide detailed information on these and other extraction methods as we continue.
CO2 extraction is considered to be the gold standard within both the CBD and THC industries. Often referred to as “solventless” (which isn’t strictly true), CO2 extraction is one of the cleanest and most reliable ways to divorce CBD-rich cannabis of its precious cannabinoids.
What is CO2 extraction for CBD?
CO2 extraction uses carbon dioxide, one of the world’s most abundant and benign molecules, to remove cannabinoids, terpenes, and other substances from hemp or cannabis. Highly pressurized CO2 gas is passed through mature cannabis buds, removing oils and other substances.
Subcritical vs. supercritical CBD extraction
There are two primary forms of CO2 extraction: subcritical and supercritical. These are chemical terms related to temperature. Subcritical CO2 extraction takes place below the liqueficiation temperature of the oils present in Cannabis sativa, and supercritical extraction takes place above this “critical” temperature.
Subcritical CBD extraction provides better purity, but it takes longer and yields less. Supercritical extraction, on the other hand, delivers better yields, but it brings undesirable waxes and chlorophyll along for the ride.
How does CO2 extraction work?
CO2 extraction facilities vary widely in terms of complexity and size. Each type of CO2 extraction, however, operates under similar principles:
- An airtight environment is established
- Cannabis buds are placed in a chamber
- CO2, either hot or cool, is passed through the cannabis buds at high pressure
- Cannabinoid-rich concentrate accumulates in a reservoir
Is CO2-extracted CBD oil safe?
CO2-extracted CBD is one of the safest forms of CBD-rich cannabis extract. Experts generally credit this safety with the “solventless” nature of CO2 extract.
From an extremely nitty-gritty technical perspective, CO2 extraction isn’t strictly solventless. CO2 is, after all, a solvent.
The reason CO2 extraction is called “solventless” is because it doesn’t leave any residual solvents behind. Any CO2 remaining in CBD-rich hemp extracts evaporates almost instantly.
Even if CO2 were left behind in CBD extract, this benign chemical wouldn’t be harmful. You’ll see as we continue that CO2 extraction’s solventless status contributes significantly to this method’s desirability.
Ethanol extraction remains surprisingly popular within the CBD industry. Compared to using CO2, ethanol extraction is considerably cheaper, and ethanol extraction facilities are easier to construct. This extraction method could never, however, be considered as clean as CO2 extraction.
Why is ethanol used for extraction?
Operating an ethanol extraction lab entails relatively low startup costs. Ethanol efficiently removes cannabinoids, terpenes, and other substances from cannabis buds.
According to the federal government, ethanol is generally regarded as safe (GRAS) as a food additive. Ethanol is commonly used as a preservative in various types of food and beverages.
It’s impossible to fully recover ethanol from cannabis extracts. Due to this substance’s GRAS status, however, producers do not view this inevitable contamination as particularly problematic.
How does ethanol extraction for CBD work?
Extraction-grade ethanol is expensive. As a result, extractors often begin the ethanol extraction process by sourcing used ethanol.
Then, the ethanol is passed through the cannabinoid-rich cannabis material. Cannabis concentrate accumulates in a reservoir.
Ethanol tends to extract chlorophyll in addition to desirable components of cannabis. As a result, further refinement processes may be necessary.
Is ethanol or CO2 extraction better?
Research indicates that ethanol may be a carcinogen. While residual ethanol in cannabis extracts may be less harmful than residual hydrocarbons, this potential risk is enough to convincingly establish CO2 extraction as the safer extraction process.
Why is CO2 better than ethanol?
CO2 is a benign compound that does not need to be recaptured after use. Extraction-grade ethanol, however, is an expensive resource that must be recaptured. When ethanol is eventually discarded, it often causes environmental harm.
Is ethanol extraction for CBD safe?
Ethanol is a volatile compound. It is, however, less volatile than hydrocarbons, making ethanol extraction safer for producers.
It is unclear whether ethanol-extracted CBD is safe for consumers. More research needs to be conducted into the toxicity of residual ethanol left behind in CBD extracts.
CBD extraction methods that don’t involve solvents are the safest and purest for consumers. They are, however, time-intensive and inefficient.
What is CBD rosin?
The term “CBD rosin” is commonly applied to CBD extracts that have been produced using solventless extraction processes. Since CBD rosin is produced purely using heat and pressure, it is incapable of containing any residual solvents.
Is CO2 extraction better than cold-pressed?
CO2 extraction is more efficient than extracting CBD using either hot or cold-pressing techniques. Since CO2 does not pose a residual solvent contamination risk, most producers don’t find solventless extraction to be worth the additional time investment and reduced yields.
Can you extract CBD with water?
Steam distillation is often used to purify CBD extracts produced using other solvents. Some extractors, however, rely on water vapor as their primary extraction medium as well.
Like other forms of solventless extraction, CBD water extraction is time-intensive, and it doesn’t deliver impressive yields. Water vapor CBD extraction is also remarkably tricky to pull off, making other solventless extraction methods more desirable.
Other hemp extraction methods
We’ve covered the three most popular CBD extraction methods. There are a few less-desirable options we should touch on, however.
Petroleum-derived hydrocarbons, such as butane and propane, are commonly used to produce hemp and cannabis extracts. While popular, hydrocarbon extraction processes leave behind residual solvents that could be considerably more harmful than ethanol.
The ketone acetone is commonly used as a nail polish remover and paint thinner. Some extractors also use this noxious substance to produce cannabinoid extracts. This extraction solvent is, however, generally considered to be unsafe.
Is CBD extraction profitable?
Even the most expensive CBD extraction processes can be profitable. Here are some tips to make your operation and profitable as possible:
- Source inexpensive biomass from local farms
- Invest in an extraction process that costs more up front but less over time (like CO2)
- Seek out bulk distribution agreements that allow you to unload large quantities of extract at once for contractually agreed-upon prices
Is CBD extraction legal?
Extracting CBD is legal as long as both your starting substance and finished extracts contain less than 0.3% THC. Ongoing efforts in Congress seek to increase this legal limit to make it easier for extractors to produce compliant products.
How do I choose the best CBD extraction method?
We encourage you to choose the safest and most environmentally friendly extraction techniques. Since CO2 extraction delivers the best yields over time while remaining efficient, we believe that this method is ideal. Under the right circumstances, solventless extraction techniques may also be appropriate.