Cannabis extraction methods all do the same basic job: they separate the cannabinoids and terpenes in the plant’s resin from the plant material itself. Whether that happens with a solvent like CO2, butane or ethanol, or without one, using ice water, heat and pressure, shapes the texture, flavor and strength of what ends up on a menu. Here’s how each method works and which products it makes.
Why cannabis extraction methods matter to shoppers
The method behind a concentrate tells you a lot before you open the jar:
- Texture. Shatter, budder, sauce, hash and rosin look and handle differently because of how they were made and finished.
- Flavor. Some methods keep more of the plant’s original terpenes; others strip them out and add flavor back later.
- Strength. Concentrates typically run well over 50% THC, several times the strength of flower.
- Solvent or not. Some people prefer solventless products; others are happy with a well-made solvent extract.
Knowing the method helps you compare products on a concentrate menu by more than the THC number.
Solvent extraction and leftover-solvent testing
Solvent-based methods wash the resin off the plant with a liquid or pressurized gas that dissolves cannabinoids and terpenes. The solvent is then removed, leaving a concentrated oil. Solvents differ in what they pull: hydrocarbons tend to leave water and pigments like chlorophyll behind, while ethanol also picks up compounds such as flavonoids.
A well-run lab purges the solvent afterward, and testing labs can check for any that remains. On a Michigan label, look for the name of the testing lab and the test date.
CO2 extraction
Carbon dioxide becomes supercritical above about 31°C (88°F) and roughly 74 bar of pressure. In that state it has no separate liquid and gas phases, and it dissolves cannabis compounds well. By adjusting temperature and pressure, processors can target different compounds, and when the pressure drops, the CO2 turns back into a gas and leaves the extract.
CO2 is non-flammable, non-toxic and easy to remove, which is a large part of its appeal. CO2 extracts can be used as they are or refined further.
Hydrocarbon extraction and live resin
Butane and propane are the hydrocarbons behind butane hash oil, or BHO, and many glassy or creamy concentrates: shatter, wax, budder and sauce. The solvent is run through plant material in sealed equipment and recovered, and the oil is purged, then whipped, cured or left to set depending on the texture the maker wants. BHO is strong: a medical toxicology study described it as containing up to about 90% THC.
Live resin applies the hydrocarbon method to plants frozen right after harvest instead of dried and cured. Freezing helps hold on to terpenes that drying can lose, so live resin is meant to taste closer to the living plant. Hydrocarbons are the usual route to live resin, but not the only way to make a "live" product, as live rosin shows below. Our guide to live resin vs live rosin compares the two.
Ethanol extraction, crude and distillate
Ethanol, the same alcohol found in drinks but at far higher purity, is used to soak or wash plant material at large scale. Because it also pulls chlorophyll, waxes and flavonoids, the first product is usually a dark crude oil that needs more work.
That’s where distillate comes from. Crude is typically winterized, mixed with ethanol and chilled so fats and waxes separate out, then filtered and heated to activate the THC. Finally it’s distilled under vacuum, which separates compounds by boiling point and leaves a clear, highly concentrated oil. Distillate has little flavor of its own, so terpenes are often added back for vape carts.
Home-scale oil and butter infusions
The simplest extraction happens in a kitchen. Decarboxylated cannabis is warmed gently in butter or oil, then strained, and the fat carries the cannabinoids into whatever you cook. The result is far less concentrated than a lab extract, and its strength depends on your starting material and what’s lost along the way. Researchers have even used olive oil as an extraction solvent, and it can preserve terpenes well. If you make an infusion, label it clearly and keep it away from children and pets.
Solventless: ice water hash, rosin, dry sift and pressed hash
Solventless methods separate the trichomes, the resin glands on the flower, using cold, water, heat, pressure or screens instead of chemicals:
- Dry sift. Dried cannabis is beaten or tumbled over fine mesh screens so the trichomes fall through as a powder called kief. A 2021 review put dry-sift kief at roughly 35% to 50% THC. Our guide to kief covers it in detail.
- Ice water hash. Plant material is stirred in ice water so cold, brittle trichomes snap off. The water is filtered through a series of mesh bags, and the resin is collected and dried. Potency is roughly similar to dry sift, depending on the starting material.
- Rosin. Heat and pressure squeeze the resin out of flower, kief or hash. Rosin pressed from ice water hash made with fresh-frozen plants is sold as live rosin.
- Pressed hash. Kief or ice water hash pressed into a solid block, a long-established method.
For more on how live rosin is made, see our solventless and live rosin guide.
Which products come from which method
| Method | Solvent | Common products | What to know |
|---|---|---|---|
| CO2 | Supercritical CO2 | Vape oils, oils for refining | Non-flammable; settings can target compounds |
| Hydrocarbon | Butane or propane | Shatter, wax, budder, sauce, live resin | Wide range of textures; purged after extraction |
| Ethanol | Ethanol | Crude oil, distillate, tinctures | Distillate is refined toward nearly pure THC |
| Ice water | None | Ice water hash, live rosin after pressing | Strength depends on the starting material |
| Rosin press | None | Rosin, live rosin | Heat and pressure only |
| Dry sift | None | Kief, pressed hash | Simplest method; powdery result |
| Kitchen infusion | Butter or oil | Infused butter, oil and edibles | Far less concentrated |
For a closer look at the concentrate types themselves, see our concentrates guide.
Safety and the law: why solvent extraction is not a DIY project
Butane and propane are highly flammable gases that are heavier than air, so they can pool near the floor and ignite from a spark or a pilot light. Burn units have documented the results. One Colorado burn center admitted 29 people with burns from making butane hash oil between 2008 and 2014; most needed skin grafts, and six needed a breathing tube to protect their airway. Another burn center reported 101 patients with these injuries from 2007 through 2014, three of whom died.
Leave solvent extraction to licensed processors with professional equipment. Solventless methods such as pressing rosin use no flammable solvents, though they still involve heat and pressure. For what Michigan law allows adults to possess and do at home, see our Michigan cannabis law guide. 21+ only. Please consume responsibly.
