Processes that aim to remove oil or resin from cannabis plant material to make a concentrate product. Extraction methods can use solvents such as butane, protane, or CO2 in a closed-loop system to produce BHO, PHO, or CO2 extracts, or can use heat and pressure to remove oils, as in making rosins or hash. Different extraction techniques can produce a variety of concentrates, including wax, shatter, oil, rosin, hash, and many more, and new extraction methods are created all the time.
“I had a bunch of trim left over after harvesting so I decided to extract it in a rosin.”
What is extraction?
There are many types of cannabis extraction and methods have been around for hundreds of years, including pressing hash into bricks, and charas, or rolling finger hash into balls. With advances in technology in the past couple decades, cannabis extraction has become much more sophisticated.
Many extraction methods today use solvents to remove cannabinoid- and terpene-rich oils from the cannabis plant. Only legal, licensed operators should create cannabis extracts with solvents, because these chemicals are usually flammable and misuse can lead to fire and injury. They required skilled, trained professionals.
Extracts can be made through solventless methods as well, such as rosin or ice water hash, and these can be made at home. To make rosin, a press with two heated plates compresses cannabis material into a wax sheet, creating an oil. Ice water hash is made by freezing the trichomes of cannabis material while in an ice water mixture, and then breaking them off through agitation.
Solvent vs. solventless extraction
Solvent extraction methods use chemicals such as butane, propane, hexane, and more, to strip cannabinoid- and terpene-rich oils from the cannabis plant. Plant material and a solvent, or combination of solvents, are placed in a closed-loop system for hours; after removing the cannabis oils, the chemicals are then purged out. The resulting product is usually refined more before packaged and sold as a concentrate.
Common solvent extractions include BHO, PHO, CO2, and more, and often come as waxes, shatters, and oils. The oil in vape pens typically comes from a solvent extraction process.
Concentrate products are allowed to have a certain levels of residual solvents in them, but levels vary state to state. It is important to only purchase concentrates from a legal, licensed operator to ensure the product has been properly tested for residual solvents.
Solventless extraction methods do not use chemicals. Instead, they use temperature and physical manipulation: For examples, making rosin requires heat and compression, and making ice water hash requires freezing temperatures and agitation.
Some consumers prefer solventless extractions because they don’t use chemicals at all and can be made at home.