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CBD Extraction

You got your feet wet with our CBD Basics article and then took your learning to the next level with our ECS article and Entourage Effect articles. CBD Extraction covers the extraction process from the ground to the final product.

The first part of this article breaks down how hemp goes from the ground to the finished product in seven steps. The second part of the “lesson” briefly talks about a few of the different extraction processes and their pros and cons. There are several extraction methods, but in the interest of keeping this lesson a reasonable length, we won’t mention all of them. However, the method used to extract the THC, terpenes and other compounds is determined from the type of product that the formulator wants to create. 

First Things First

Let’s clear up one thing right up front. The growing, harvesting, and creation of CBD products is legal. 

In December of 2018, the “2018 Farm Bill” was signed into law. It removed hemp, from the definition of marijuana in the Controlled Substances Act (CSA). Hemp as defined in the bill as cannabis (Cannabis sativa L.) and derivatives of cannabis with extremely low concentrations of the psychoactive compound delta-9-tetrahydrocannabinol (or THC) as long as it contains no more than 0.3 percent THC on a dry weight basis. This means that CBD products can be legally sold across the US as long as it meets the conditions of the 2018 Farm Bill.

Hemp is a variety of sativa. The term “hemp” is used to classify cannabis that contains less than 0.3% THC (or less). Plant breeding has increased the THC level to the point where it can account for up to a quarter of a plant’s total weight. Scientists have found that breeding high-THC plants with hemp-type plants can make a new plant that produces high levels of CBD.

From the Ground to the Marketplace

Many people wonder how cannabis/hemp goes from something that comes out of the ground with flowers, seeds and stalks and somehow turns into the CBD products they buy in the marketplace. Typically, the hemp goes through 7 stages before it is packaged and marketed. We assume by now that you understand most hemp is grown in the ground so that leaves us with six of the steps to talk about.

Harvest: Industrial hemp is harvested like other agricultural products that use farm equipment to harvest crops. Combines, similar to the ones that harvest other crops, are used to cut hemp stalks used for industrial products; however, because these machines would compromise the quality of the flower, specialized machinery is used. A hemp harvesting machine cuts the the stalk and the flowers, carefully bundles them to avoid damages.

Cure: Once the hemp has been harvested it needs to be dried out. This part of the process is called curing. The bundles of hemp are hung to dry in a well ventilated area. After about 3-4 weeks the flowers and leaves are separated from the stems and stalks. NOTE: There are other ways to dry out the hemp such as using a vacuum oven to bring the moisture content down to the right levels for extraction.

Bucking: Also called “shucking”, this process separates the flowers from the stalk. This process is generally done by machines that gently separate the flowers without damaging their essence. The idea is to avoid compromising the important compounds particularly the terpenes that play a role in “The Entourage Effect“.

Extract: The flowers are now ready to be extracted. This is the part of the process that removes the cannabinoids and other compounds such as terpenes from the flower. This process yields a thick oil. But before that happens, there are a few questions that need to be answered.

It is important to consider the desired outcome of the extraction. This will lead to the type of CO2 process used – supercritical; subcritical CO2 extraction; or a combination of the two.

The next set of questions determines the product goals defined by the formulator once the hemp oil is extracted. Will it undergo winterization to remove waxes and other unwanted materials undesirable? Will it be distilled? Will it need to be decarboxylated for use in food products or oral dosage forms (capsules, lozenges, tinctures)? The post-extraction processing/purification pathway defines the CO2 extraction process. What if the formulator wants to use isolate?

Manufacturing CBD isolate requires several additional steps – winterization; filtration; decarboxylation; distillation; and crystallization. The final crystallization process involves 5 steps.

Formulate: The type of CBD product is determined by its formulation. CBD isolate is used in a number of products such as edibles, pain relief topicals, skin care and many other CBD products. CBD oil is generally used for tinctures; however, it can be used in other products.

Test: Once you’ve settled on the formula you want to market most legitimate CBD manufacturers send samples of the formula to an independent testing lab where it is isolates and tests the compounds found in CBD oil or any other CBD product that is submitted. The lab looks for other things including toxic heavy metal contamination and other microbial impurities. The results of their tests are put into a report called a Certificate of Analysis (or COA). The certificate also indicates the levels of THC and CBD in the product. If you want to know how to read a COA, you can find out here.

Market: Once a company receives a COA for the product they formulated, they will begin creating packaging and putting together a marketing plan to sell their products. 

The Extraction Process

There are several methods for extracting CBD from hemp including, but not limited to CO2; ethanol; dry ice; hydrocarbon; and vegetable oil extraction processes. Each of them has their pros and cons, but for this lesson we will focus on Supercritical CO2 Extraction and Ethanol (alcohol) Extraction.

Supercritical Carbon Dioxide (CO2) Extraction: CO2 extraction is the so called “gold standard” of extraction processes. CO2 is a precise and powerful solvent under pressure. Temperature variations help extract certain compounds from the plant without destroying their essence. The combination of terpenes and all other cannabinoids in the hemp flower create full spectrum oil.

The CO2 process starts with ground up plant material placed into an extraction vessel. (Think coffee ground-sized.) A pump forces supercritical CO2 into the vessel where it breaks the trichomes and releases the sticky oil contained in the plant material.

Pros

The CO2 extraction process delivers purity by eliminating harmful solvent residues and reducing unwanted compounds in the finished product. The process also removes pesticides, mold, mildew, bacteria and insects during the process.

CO2 extraction can be fine-tuned by adjusting temperature and pressure. This makes processing quicker and more efficient while also targeting only the desirable compounds in the hemp biomass.

The CO2 process is capable of extracting targeted compounds such as terpenes and flavonoids from the plant without destroying their essence to capture the fullest potential from top quality hemp biomass to extract. Increasing or decreasing the pressure changes which particular terpenes and cannabinoids come out of the process.

The carbon dioxide process used for hemp extraction is a closed-loop system. CO2 is recoveredcollected, and recycled. It leaves behind no chemical solvent residue. Because of this process, it can also support specific “green” brand attributes that are often associated with hemp products.

Cons

The cost of small scale CO2 extraction equipment can cost between $40,000 to $60,000. Large scale equipment can cost upwards of $400,000 and more. Comparable equipment costs for ethanol and other extraction equipment costs less.

It takes 6-10 CO2 extractors to deliver the same output as a single ethanol extractor.

Because of its longer and more aggressive nature, this process could cause some damage to the cannabinoids and the terpenoids in the extract.

Winterization drives up equipment and operating costs.

Ethanol/Alcohol Extraction: Ethanol extraction is one of the most common, oldest, and least expensive methods to extract CBD from hemp. It is a proven method that’s considered to be an efficient way to extract CBD from hemp. Alcohol is generally considered safe; however, purifying it from the final product requires a good deal of caution due to the potential flammability of alcohol. 

Ethanol extraction requires soaking the hemp plant in ethanol, which runs through packed plant matter, stripping valuable compounds from it along with chlorophyll. After the solvent has gathered enough cannabinoids and terpenes, the liquid is strained and then heated. After evaporation, the extract is suspended in a carrier oil to thin it down and improve its bioavailability. This results in a very clean, balanced, full-spectrum CBD hemp oil.

NOTE: There is a method called “cryogenic ethanol extraction” (or as it is also referred to “Cold Ethanol Extraction) that provides the best of both worlds. It enables the extraction of high quality CBD crude, distillates, and isolates using ethanol complemented by the safety of CO2 extraction. We will not cover cryogenic or any other types of ethanol extraction in this “lesson”, but you can read about it by clicking on the above link. 

Pros

If done correctly, ethanol extraction can reduce the need for dewaxing or winterization. Winterization is the process of removing lipids from the cannabis extract.

Great for creating for full spectrum hemp extracts and tinctures. The extraction process boils off any unwanted terpenes and flavonoids, leaving an odorless, potent cannabis oil that can be absorbed under the tongue. 

Ethanol extraction operations are simple to set up and only requires an energy consumption of 20%.

Oil and ethanol extraction equipment can come in both batch or continuous systems, depending on the scale of your company. A batch system will operate one cycle at a time, allowing you to control exactly when the equipment is running.

Continuous units operate using continuous distillation methods. These are great for companies with much larger production processes.

Ethanol extraction is often favored by high-volume extraction companies because it typically has lower electrical costs per pound than CO2 extraction. Labor costs are also typically lower per pound of biomass produced. Also, ethanol machinery is reasonably cost-effective especially when considering the higher output yields and storage capabilities.

Cons

Ethanol is a polar solvent and will pull more water soluble components from the plant including chlorophyll, which tends to extract fewer cannabinoids and terpenes than other popular extraction methods. Removing chlorophyll will requires difficult post-processing often times using activated charcoal. Unfortunately, activated charcoal can absorb active compounds like THC and CBD reducing the potency of the product. 

Because of the post-processing process, ethanol extraction takes much longer than hydrocarbon and other forms of extraction. 

Ethanol has a high boiling point which can drag out the recovery process. 

Ethanol extraction requires tremendous precision and skill to isolate specific cannabinoids and remove all traces of solvent. Post processing which is required for ethanol extraction, is much more labor intensive than CO2 extraction and involves the use of several different methods of refinement and filtration.

Conclusions

Like other things related to CBD things evolve. As demand for more products increases, the need to increase crop yields and reduce processing and extraction times will be needed to meet market demands and of course increase the bottom line. Growing hemp can be a tricky, labor-intensive crop. It is far from a commodity. An emphasis on quality over quantity is likely as demand pushes on supply. Quality control and safety will continue to play important roles leading to higher quality, safer products. All of this means we can expect to see improved extraction equipment in the future. Sea King CBD will continue to keep their eyes on extraction trends. Stay tuned.

Peace of Mind Guarantee

Remember, when you make a purchase from Sea King CBD you are also getting our 100% Peace of Mind Guarantee. Plus, all of our CBD is tested by third party laboratories plus.

References

[1] Apeks Supercritical. “How to extract CBD oil – The extraction process & how to make CBD oil” https://www.apekssupercritical.com/cbd-extraction-process/

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