Extraction 101

The extraction of the cannabis plant to make concentrates is becoming increasingly popular in the industry. The point of extraction is to isolate or “concentrate” the desirable parts of the plant, such as cannabinoids and terpenes. At the same time, removing the undesirable parts of the plant like chlorophyll and other plant material. Depending on the composition of the plant, extraction can be used to make a concentrate that has high THC, high CBD, and much more.

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“Dabbing” is the act of inhaling concentrated cannabis.

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The art of extraction is not new and has been around for a long time. While the industrial uses of cannabis were thought to have been discovered first, extraction still has a long and storied history. Some historians claim that the first use of cannabis as a concentrate was as early as 1500 BC (1). In the 19th century, cannabis extracts could be found in the United States in the form of tinctures. These medicines were sold as a cure-all for baldness, toothaches, impotency, typhoid fever, and more (1).

One of the major advantages of extraction, is that it can turn trim and other less valuable parts of the plants, into a new finished product. For example, even though trim usually has a low cannabinoid level (usually 1-5%), when extracted, the resulting concentrate can still have a potency of 60% and higher. However, with extraction the best indicator of a quality concentrate is the quality of flower, trim, and/or leaves being extracted from. The higher the potency going in, the higher the potency coming out.

Extraction comes in 2 major methods: Solvent Extraction and Non-Solvent Extraction. Both of these types of extraction have multiple processes that will each give you a unique final product. Let’s take a look.

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Solvent Extraction

A solvent is: “a substance capable of or used in dissolving or dispersing one or more other substances” (2). Solvent extraction uses a solvent to attach to and collect all the desirable compounds like cannabinoids and terpenes. For example, if butane is used, the butane will attract and combine with the desired chemicals. This leaves a product with cannabinoids, terpenes, and butane all together in one solution. Since butane can be harmful if smoked, the “purge” process is used to remove the butane or other solvent (“Purge Process" discussed below).

Popular solvents include: alcohol, butane, propane, hexane, and more. Different solvents will attract and pull different chemicals out of the plant. Because of this, each specific type of solvent extraction can produce a different flavor, potency, color, and consistency.

Solvent extraction usually has higher cannabinoid and terpene potency compared to non-solvent extraction. Potencies of solvent extraction typically range from 60 – 99+%. Most non-solvent extraction methods do not come close to these numbers.

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Common types of solvent-extracted concentrates include:

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Alcohol-Extracted – Alcohol is one of the oldest solvents used to extract cannabis. There are many types of alcohol extraction. Common products that utilize alcohol extraction include: tinctures, “Iso Oil”, and Rick Simpson Oil.

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Butane Hash Oil (BHO) – Butane is probably the most popular solvent used in the cannabis industry. Butane extraction is a fairly easy process that can produce high potencies. Shatter and Wax are the most popular types of BHO.

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CO2 – CO2 (carbon dioxide) extraction is becoming increasingly popular in the industry. While it is generally more expensive than BHO, it is thought to offer a healthier product. CO2 extraction is also safer than butane extraction because CO2 is non-flammable. CO2 Oil is commonly used in e-pen cartridges.

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Live Resin – Live Resin involves the “fresh frozen” process, where plant matter is frozen immediately after harvest. This allows more terpenes to be saved and extracted, allowing Live Resin to have tremendous flavors. Live Resin is generally extracted with butane.

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Molecular Separation – The newest trend in solvent extraction is molecular separation. This process allows for some of the purest forms of different compounds, and can reach potencies of nearly 100%. Isolates and Distillates are common types of molecular separation.

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Purge Process

After a solvent attracts and combines with the desired cannabinoids and terpenes, a single solution is left over. The solvent needs to be removed from this solution so that it is not consumed along with the intended cannabinoids and terpenes. The process of removing the solvent is called: the purge process.

There are different methods for purging a cannabis concentrate depending on the type of extraction process that was used. Methods for purging include: ovens, vacuum ovens, and other methods of heating. Purges can vary in length, temperature, and more. A solvent’s boiling point is important when deciding the best way to purge a solution, as some solvents are easier to purge than others (1).

A closed-loop system is a type of equipment that is often used during the purge process. Essentially, what a closed-loop system does is it allows for a solvent to be re-used. The system collects the solvent during a purge and recycles it back into a tank to be used again. Not only are these systems cost-effective, they are also less dangerous because it limits the possibility of a solvent leaking into the open air.

The biggest problem with solvent extraction is the potential danger. Most solvents that are used are highly flammable. As a result, solvent-extraction should only be done by professionals with proper equipment. Over the last few years, there have been plenty of residential explosions due to inexperienced extractors not operating properly. A simple flame has the potential to cause a massive explosion.

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Non-Solvent Extraction

Non-Solvent extraction does not use a solvent to “concentrate” chemicals such as cannabinoids and terpenes. Instead, the trichomes of the cannabis plant are separated from the rest of the plant using a manual or mechanical process. Because no potentially harmful chemicals are used, non-solvent extraction is considered a more natural process compared to solvent extraction.

While non-solvent extraction is often considered a safer alternative to solvent extraction, it typically produces a much less potent product. Potencies generally range from 30 – 70% depending on the non-solvent method applied. In comparison, some solvent extractions have cannabinoid percentages that are nearly 100%.

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Common types of non-solvent concentrates include:

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Kief – The fine powder that is usually found at the bottom of a 3-chamber grinder. This powder is made up of many trichomes that have passed through a small screen.

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Dry-Sift – This is an old-fashioned method of simply using a fine screen to sift the trichomes of the plant away from undesired biproducts.

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Water Hash – Water hash is typically made by placing cannabis into ice cold water. The trichomes become brittle, and when the water is agitated, the trichomes break apart from the rest of the plant. The water is then fed through a series of screens to separate the trichomes.

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Rosin – Heat and pressure are used to squeeze the trichomes and release the chemicals inside. This is often done by placing flower on parchment paper, and then heated using a hair straightener.

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References

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Published: 8/1/18