TABLE OF CONTENTS
Your favorite cannabis concentrates, edibles, and topicals are made through a cannabis extraction process that isolates the plant’s therapeutic resin and infuses it into the product. Here, we cover the most common types of cannabis extraction processes.
An ancient technique
Cannabis extraction has a long history dating back thousands of years to the Indian charas, a cannabis concentrate made by rubbing the plant to remove its sticky trichomes. The resin balls or sticks could be smoked in a chillum pipe.
Today, we can use cutting-edge equipment and chemical solvents in laboratory settings to quickly, safely, and efficiently create a pure and potent concentrate. Extraction methods that don’t use chemicals can also produce high-quality concentrates.
- Hydrocarbon extraction (also known as butane hash oil extraction)
- Ethanol extraction
- Supercritical carbon dioxide extraction
- Dry sifting
- Ice water extraction
- Rosin pressing
Types of Cannabis Concentrates
Cannabis concentrates are high-potency products that come in various consistencies and potencies. Here are the most common types of solventless and solvent-based concentrates.
- Shatter is hard, brittle, translucent, has relatively low terpene levels, and is made with CO2 or hydrocarbon extraction.
- Crumble, also known as honeycomb wax, has a dry and crumbly consistency and is made using hydrocarbon extraction.
- Budder has a soft and creamy consistency and is made with CO2 or hydrocarbon extraction.
- Live resin has a grainy and saucy consistency, is made using hydrocarbons, and has a relatively high concentration of terpenes from fresh-frozen cannabis instead of dried cannabis.
- Terp sauce is a blend of cannabinoid “diamond” crystals and liquid terpene sauce. This concentrate is made with hydrocarbons.
- Distillate is a highly refined concentrate containing 90%+ of one cannabinoid and can be made using hydrocarbon or ethanol as a solvent.
- Isolates are cannabinoid crystals or powders that contain 99.9% THCA or CBD, made using hydrocarbons as a solvent.
- Rosin has a dense and sappy consistency and is made by pressing the dried plant material at high pressures.
- Live rosin is similar to rosin but uses bubble hash as its starting material instead of dried cannabis flower.
- Hash has a firm and malleable consistency and is made by compressing cannabis trichomes (kief) into balls or other forms.
- Kief refers to a pile of powdery and sticky trichomes obtained through dry sifting or ice-water extraction.
- Bubble hash is a high-quality hash made using fresh-frozen cannabis through an ice-water extraction process.
Solventless extraction methods do not use chemical solvents but heat, pressure, or ice water to separate the trichomes from the dried plant material.
Dry sifting on a basic level can be done in a cannabis grinder when the kief falls through the middle chamber to the bottom chamber. Commercial producers use a series of mesh screens and shake the dried material over them to break off and filter the trichomes (kief).
Ice water extraction involves submerging cannabis in a bucket lined with filter bags (bubble bags) and filled with ice water. The idea is to freeze and break off the trichomes by gently stirring the material. The trichomes are filtered through the bags and collected.
Rosin pressing involves compressing dried plant material to crush out the resinous oil. A similar process can be done using a simple hair straightener on the low setting and some parchment paper covering the nugs.
Solvent-based extraction occurs in a closed loop system using chemical solvents such as ethanol, hydrocarbons, and supercritical carbon dioxide. These methods require more safety precautions to protect against toxicity, fire, and explosions.
Hydrocarbons such as propane and butane are used due to their relatively low boiling point compared to other methods. This allows processors to extract more terpenes, which are known to have a lower boiling point than cannabinoids.
During the hydrocarbon extraction process, hydrocarbons are passed through the cannabis, dissolving the trichomes from the plant matter. The crude oil undergoes a vacuum purge to remove the residual solvent from the final extract.
Ethanol is generally used for high-volume hemp extraction. As a polar compound, ethanol can dissolve various compounds, including an excess of chlorophyll, which can create a bitter or harsh taste and requires further distillation to remove.
Ethanol extraction can be performed under warm or cold conditions. Warm temperatures can dissolve a greater range of cannabis compounds, good for full-spectrum extraction. Cryogenic (cold) extractions can reduce the fats and lipids in the extraction process, thereby reducing the need for winterization and streamlining high-volume production.
Supercritical carbon dioxide (CO2) is a state where this solvent acts like a liquid and a gas, diffusing throughout the dried material and dissolving the trichomes like a liquid. Supercritical CO2 is considered one of the most eco-friendly and safest extraction methods.
During this process, extractors pump the CO2 at high pressures and temperatures through the cannabis to dissolve the cannabinoids. A subcritical extraction uses lower temperatures and pressures to remove the terpenes and the cannabinoids at a higher temperature and pressure. Winterization using ethanol may be required to remove fats, lipids, and waxes.
Cannabis Training University’s Master of Cannabis program provides a well-rounded education on the cannabis industry. Learn the latest laws and regulations and different cannabis extraction techniques. You’ll also learn to grow weed and make extracts and edibles at home.