- Extraction of cannabis is performed by either solvent or non-solvent (solventless) methods. All methods have safety, potency, and labor-intensive considerations.
- For “cleaner” methods that can be performed in smaller batches, solventless is the way to go.
- Solvent methods are often used commercially and may have more predictable outcomes in potency and variety.
There are many methods to obtaining a finished cannabis product, and ideas may come to mind in the form of extraction equipment, ovens, submersion, etc. These steps are just some that are illustrated in the two main methods of extraction, solvent, and solventless, that remove cannabinoids from cannabis.
Learning more about the solvent and solventless extraction methods can aid you in being comfortable and informed about the product you’re buying, so let’s break this down to help you navigate the world of cannabis:
Solvent-based Cannabis Extractions
Solvent-based extractions produce mostly extracts, such as live resin, shatter, wax, and vape oils.
Solvent-based extractions work by dissolving trichomes from the cannabis plant by way of solvents, or chemicals, before removing the residual solvent itself. This method is preferred by some because it can be used on a large scale for manufacturing. Diversity and potency have a predictable and favorable outcome with this method as well.
Issues regarding this method include organic and safety concerns. In removing the solvent, a teeny bit, even if it’s only 0.1%, is left behind in the product which restricts this method from being a totally “clean” method. Solvent-based extractions can be very dangerous if not carried out properly as it can lead to fires and explosions. That’s why it’s important to leave extraction to the pros, and make sure you buy your cannabis products from a dispensary like RISE where all the products are lab-tested for residual solvents and other chemicals.
Types of Solvent-Based Cannabis Extraction
Cannabis concentrates and extracts can both be produced by carbon dioxide. Extraction equipment and specific training are required. Supercritical CO2 extraction is used to achieve extracts and is not only dangerous but illegal in most states and must be performed properly. Extreme pressure and very high heat are used to fluctuate mass to break down and separate cannabinoids and must be accomplished in a factory-safe environment. When executed in this manner, the end product is pure.
This method is commonly used in the food and beverage industry (think decaffeination of coffee) as the process generally does not leave behind any residual toxins and the solvent used is non-volatile, making it also environmentally friendly. This method is best for producing full-spectrum cannabis derivatives as terpenes are preserved wonderfully via C02 extraction to present cannabis extract with unique flavors and scent profiles. [Source]
Like carbon dioxide extraction, hydrocarbon extraction through the use of butane or propane requires special equipment and instruction as well as a “blast-proof” work environment. In other words, this is not a DIY project as it is potentially extremely dangerous! The equipment involved can be open-loop or closed-loop. What’s the difference? Open-loop is cheaper and very dangerous and closed-loop is safer but very expensive. Both are commercially used.
Butane and propane are light hydrocarbons. Butane is primarily used but some manufacturers use a 70/30 percent ratio of butane and propane to preserve more of the cannabis plant’s terpenes.
Full-spectrum cannabis extract can be accomplished due to the ability to use low heat in the extraction process thanks to butane and propane’s low boiling point. This method is also used in the fragrance industry.
The advantages of this method include efficiency in the preservation of cannabis compounds, a higher yield in therapeutic compounds compared to carbon dioxide extraction, and versatility in the cannabis compounds produced such as shatter, crumble, and live resin. In fact, the hydrocarbon solvent is the only method that can produce live resin which is a high-quality oil.
The process of hydrocarbon extraction is summarized in these steps; dewaxing, centrifugation, and finally winterization, which is the process of using cold ethanol.
The butane or propane solvent is then gassed off using heat and a vacuum oven. Because strain purity is achieved so well with this method, it is one of the best ways to make high-end dabbable concentrates, such as budder, butane hash oil, shatter, resin, wax, crumble, and honeycomb. It is also used to make ingredients for edibles, topicals, tinctures, and vape cartridges.
Also referred to as ethyl alcohol or alcohol extraction, ethanol has been used for botanical extraction for many years and is deemed fairly safe and easy to use. It’s a favored solvent since it is relatively clean, leaving no residual solvent in the final product when done correctly.
Ethanol is less explosive and less toxic than both carbon dioxide extraction and hydrocarbon extraction. It is a very versatile solvent as it can be both polar and non-polar, allowing for the extraction of a wide variety of cannabinoids and terpenes. [Source]
Since cannabinoids and terpenes are fat-soluble and ethanol dissolves fat well, indigestible cannabinoid-derivative products and crude products are often produced by this method. Crude products include things like vape cartridge oil, gel caps, edibles, tinctures, and topicals.
With ethanol extraction, different outcomes can be achieved simply by changing the temperature used.
- Warm or room temperature water: a wide range of terpenes, as well as other water-soluble compounds, can be extracted along with the cannabinoids.
- Cold water: ethanol shares a likeness with fat-soluble compounds, which means this is a very efficient extraction of cannabinoids and terpenes.
After soaking in either temperature, the solvent is evaporated with a vacuum and heat. A crude concentrate is left over and then further distilled to create purified and isolated THC or CBD products through the process of chromatography. [Source]
The downside to using ethanol extraction is that it is not very good at isolating types of cannabinoids such as CBD from THC to create an individual isolate. The solvent is also not able to separate from terpenes, meaning an inability to produce a “live” end product.
Extraction via vegetable oils, like sunflower, coconut, or olive oil, is an inexpensive option that when done properly can be safely implemented at home. Olive oil is commonly used in marijuana extraction due to its efficiency in solubility and its ability to protect compounds from evaporation in the heating process. [Source]
A high yield of terpenes is achieved due to the low volatile nature associated with olive oil. The process is completed in a few easy steps:
- Decarboxylation is achieved through the process of heating the cannabis plant to transform the cannabinoids into compounds like CBD and THC.
- The cannabis is then added to the oil of choice and heated for a couple of hours, leaving behind an infused, edible oil.
- The finished product is a combination of the solvent and the extracted oil.
Unfavorable outcomes from vegetable oil extractions include: low potency and short shelf life, so products should be stored in a cool, dry place.
Solventless Based Cannabis Extractions
Solvent-free extractions produce marijuana concentrates such as hash, kief, and moon rocks. It is a cleaner method as it does not use chemicals. Instead, the trichomes are beaten or pressed off of the plant.
This is the method of extraction used by the majority of dispensaries. By using a solventless method of extraction, a better overall product can be achieved in a safe and chemical-free way.
Types of Solventless-Based Cannabis Extractions
With the ice-water extraction method, the cannabinoids are actually separated rather than extracted. The THC potency of ice water extraction depends on the potency of the starting plant material and generally falls in the range of 35-50%. That being said, one consideration is that potency control is limited in this method. In this technique, trichomes are gathered after the cannabis plant has been placed in a mesh bag and submerged in ice-cold water for some time and agitated as needed for mechanical separation. The final product is obtained after the isolated trichome completes a series of screening and drying. The leftover trichome is often pressed into patties to create ice water hash.
This method is most commonly used to make bubble hash as it produces high-quality hash for dabbing without leaving behind any solvents.
Hemp and cannabis oils are produced by cooling the cannabis plant and then crushing it under great pressure. The resulting oil can then be consumed alone or mixed with other ingredients depending on the desired end product.
The amount of oil collected through cold-pressed extraction yields less than some of the other methods mentioned. However, the oil is of higher quality.
There may be fewer adverse effects when the medicinal properties of cannabis are obtained in this organic fashion. This may be why the cold-pressed method is most used for wellness products, such as CBD tinctures and topicals.
This is similar to the cold-pressed extraction method, when temperature and pressure are used to obtain the oil. The act of compressing and heating cannabinoids with a heat-controlled hydraulic rosin press produces both oils and rosin.
Rosin pressed extraction is a popular method because it has high potency levels of THC or CBD without drastically changing the chemical profile since using a small amount of heat, rosin is produced quickly without chemical residue left behind.
Pressed Kief and Hashish Extraction
The pressed kief extraction method has similar potency control issues and THC percentage outcomes as the ice water extraction method. It involves the labor-intensive itinerary of beating dried cannabis against a screen and pressing the fallen-off trichomes. By using low heat and high pressure, kief can be manufactured into hashish or hash. You won’t find this method used commonly in the commercial level distribution due to the consumption of time and potency unpredictability.
At RISE, we take pride in aiding the cannabis movement to include the use and knowledge of cannabis for all, so if you have any more questions about cannabis extraction methods, please visit a RISE dispensary nearly or reach out to us. We’re here to help!