Cannabis Extraction: What You Need to Know
Sometimes, just smoking your cannabis isn't enough. Science has given us a number of ways to make stronger medicines by extracting the active chemicals and concentrating them into a new, stronger, product.
A cannabis extract is a product derived from a cannabis plant that contains a high concentration of medicinal or psychoactive ingredients. Essentially, cannabis extraction is a way to create a product that is either more applicable for a particular purpose or more potent than the cannabis plant material alone. Some extraction methods, such as cooking or baking with cannabis, have been around since humans first began using the cannabis plant. Other extraction methods have been developed more recently and require sophisticated equipment to complete properly. Cannabis extractions can be separated into two categories: solvent extracts and non-solvent extracts.
Extracting cannabis with a solvent
Extracting cannabis with a solvent can be accomplished in many ways. Basic solvent extractions include edible extracts, such as butters, oils, and tinctures. More advanced chemical solvent extraction methods involve sophisticated equipment, such as a closed or open loop extraction system. These types of systems generally use butane or propane as the solvent. Other chemical extraction methods use ether, lab-grade naphtha, CO2, or dry ice as the solvent to extract the cannabinoids. Popular solvent-based extract products include butane hash oil (BHO), shatter, wax, Rick Simpson oil (RSO), supercritical CO2, and cannabis distillate. Many of the solvents used for cannabis extractions are extremely flammable. For this reason, most solvent-based extraction methods are best left to the professionals.
One of the oldest and most common extraction methods for cannabis is making canna-butter or canna-oil (also known as butter or oil infused with cannabis). Many of the active cannabinoids found in the cannabis plant are fat soluble. This means they bind to fat molecules and can be extracted using butter, coconut oil, or any other substance which is comprised of a high percentage of fat. The cannabis material is mixed with butter or oil and then gently heated over a span of several hours. Once the extraction is complete, the butter or oil (now containing THC and other cannabinoids) is strained from the plant material and is ready to use for cooking or baking.
Cannabis tinctures are usually made with glycerin or alcohol. As with canna-butter or canna-oil, a tincture is an extract where the solvent (the glycerin or alcohol) is consumed along with the extracted cannabinoids. In other words, the glycerine or alcohol is used to extract the cannabinoids (via heat and time) and is then separated from the plant material. The end result is glycerine or alcohol infused with cannabis and is consumed by the end user.
Butane hash oil (also known as butane honey oil), or BHO, is a type of cannabis extract that uses butane as the main solvent. BHO is a term usually reserved for a product that is sticky and has a similar viscosity to honey. Other butane-based extractions are classified by their texture and consistency. In addition to BHO, butane-based cannabis extracts include wax, shatter, budder, honeycomb, crumble, or sap. The old school method of producing BHO was called open blasting. This method involved loading plant material in a tube and soaking it in butane. Not only was this method quite dangerous, but it was also wasteful. Today’s BHO products are usually made with a closed-loop extraction system. The butane is held in a pressurized tank that is attached to the extraction tube where the plant material is housed. The biggest advantage of a closed loop system, aside from increased safety, is that the solvent can be reused.
Rick Simpson oil
Rick Simpson oil, or RSO, is a solvent extract that is very popular among medical marijuana patients. RSO is most effectively made with lab-grade naphtha, but is also commonly made with ether. RSO is made by cooking cannabis down in a solvent to make a highly concentrated oil. RSO can be smoked, ingested, or applied directly to the skin.
Supercritical CO2 cannabis oil
Carbon dioxide behaves as a gas in the air at standard temperatures and pressure. When the pressure and temperature of CO2 are increased over what is known as the “critical point”, the CO2 can have properties between a gas and a liquid. In order to make a high quality supercritical CO2 cannabis oil, the processor needs to have the proper equipment. A supercritical CO2 device made specifically for cannabis extraction will have a liquid CO2 storage tank, a compressor, a heating element, a separator, and a condenser. After the extraction process, the CO2 pressure is released and the remaining liquid CO2 molecules convert back into a gas which then evaporates into the atmosphere. Some of the most sophisticated supercritical CO2 extraction machines will even recapture and reuse the CO2 gas.
Cannabis distillate is an extraction method that relies on molecular separation. This method enables cannabis technicians to separate the cannabinoids and terpenes from the plant material with minimal thermal degradation. The vacuum levels of this process allow the distillation of normally high boiling point products to occur at moderate temperatures. This is beneficial because the plant material is not exposed to high temperatures for very long which means less of the valuable compounds will be degraded by the heat. All in all, cannabis distillate is one of the highest potency cannabis extracts currently available.
Cannabis: extracting without a solvent
Generally speaking, a cannabis extract made without a solvent is less potent, but is also much less dangerous to produce. Making kief is something that just about any cannabis consumer can do. Automatic tumblers equipped with a kief screen take away most of the labor associated with the process. Subjecting cannabis flower material to high pressure and heat is another way to extract cannabinoids without a solvent.
Sifting cannabis trim material with a kief screen to extract the trichomes is probably the simplest form of non-solvent extraction. Kief is made by dry sifting. Dry sifting can be done by hand or with a machine, sometimes called a pollinator. Dry sifting involves shaking or moving the dried flowers and/or leaves on a fine screen (usually 120-150 micron mesh) until the trichomes fall through the screen and are collected. Once collected, the kief can be consumed as is or pressed into hash.
Ice water hash
Technically speaking, ice water is the solvent used in this extraction method, but ice water hash is being included as a non-solvent extraction method because the process is safe and there are no potentially harmful residuals. In this process, the plant material is mixed with ice water to get the trichomes cold. This is typically done in a five gallon bucket or a plastic garbage bin. Inside the holding container are a series of bags, each with a different size mesh bottom. After vigorously mixing the ice water (this breaks the trichomes away from the plant material), the bags are lifted out one at a time, and strain the plant material in the process. The first bag (largest size screen) to be removed will contain the majority of the plant material and the last bag (smallest size screen) to be removed will contain the highest concentration of THC and other cannabinoids. After the cannabis extract has dried completely, it can be enjoyed like other hashes.
The most potent non-solvent cannabis extract is rosin. Rosin is a solid form cannabis extract made by applying pressure and heat to the cannabis flowers to vaporize volatile liquid terpenes. Put another way, rosin is made when the cannabis material is put under extreme pressure, while also being heated to a desirable temperature (somewhere between 250-335 degrees F). Rosin is quickly becoming a very popular cannabis extract because it is similar in potency to solvent-based extracts, but without the potential dangers associated with the solvents during processing or as residuals. It is also significantly less expensive to produce than most solvent-based methods. For all of these reasons, rosin is quickly becoming one of the most popular cannabis extracts.
As the laws pertaining to the cannabis plant continue to progress toward legality, cannabis extracts will only continue to grow in popularity. Depending on his or her particular needs and desires, a cannabis consumer can choose from a variety of cannabis extract products. Not only do different extracts offer different potencies, but they also offer different methods of delivery. Personal preference plays a huge role in which type of cannabis extract a person will choose. The more that is learned about cannabis and all of its active ingredients, the more extraction techniques and extract products will be developed and fine-tuned. All in all, more diverse cannabis-based products mean better, more specific treatments for patients and more variety for enthusiasts to enjoy.