Cannabis Extraction: The Complete Guide to Extraction Methods

Last updated on July 28, 2026 · Originally published April 19, 2017

Cannabis extraction is the process of separating cannabinoids, terpenes and other resin components from the plant material that carries them. For many products, that separation is only the first stage. The starting material, the method, the operating conditions and the refinement that follows all combine to determine what ends up on the shelf.

Fresh-frozen cannabis extracted with hydrocarbons may be sold as live resin, or processed further into sauce or THCA diamonds. An ethanol extract may become full-extract oil, or be refined into distillate. Flower, kief or hash pressed with heat and pressure becomes rosin. The finished product is not determined by the solvent alone, but by the whole processing chain.

This guide maps that chain: the major extraction methods, what governs them, the refinement steps that follow, the products they produce, and where to find our detailed coverage of each.

Extracts and concentrates: not quite the same thing

In common cannabis-industry usage, a concentrate is any product in which the plant’s resin has been concentrated, while an extract is generally understood as a concentrate produced using a solvent. Under that convention, all extracts are concentrates, while products such as rosin and dry sift are concentrates rather than extracts.

The terminology is not fully standardized, and regulators apply it inconsistently — some jurisdictions class CO₂ products as “non-solvent” for testing purposes even though CO₂ is plainly acting as the extraction medium. We unpack the distinction further in the difference between cannabis extracts and concentrates.

The processing chain

Most concentrate production can be understood as a four-stage chain, although some solventless products require little or no refinement after the initial separation. Understanding the chain explains most of the confusion around product names.

1. Starting material — dried and cured flower, fresh-frozen flower, kief, hash, or biomass.
2. Primary separation — hydrocarbon, alcohol, CO₂, rosin pressing, dry sifting, or ice-water separation.
3. Refinement and finishing — filtration, winterization, purging, decarboxylation, distillation, crystallization, agitation.
4. Finished form — crude oil, distillate, isolate, shatter, wax, budder, crumble, sauce, diamonds, live resin, live rosin, RSO, bubble hash or dry sift.

Extraction methods at a glance

Solvent-based extraction

Solvent-based methods transfer the desired compounds from the plant into a solvent phase, which is then separated or removed. What distinguishes them is which solvent, and what else comes along with the cannabinoids.

Solvent polarity is the best starting point for understanding that selectivity, but it is not the whole story. Temperature, pressure, contact time, water content and the condition of the starting material all affect what enters the extract.

Hydrocarbon extraction (BHO)

Butane, propane or a blend is passed through cannabis in a sealed column, dissolving cannabinoids and terpenes while leaving most water-soluble material behind. The solvent is then recovered and the extract purged under vacuum.

Hydrocarbon extraction is associated with an unusually wide range of finished textures, which is why many of the concentrates you recognize by name are associated with it. It also carries the most demanding safety requirements: butane is highly flammable, and amateur “open blasting” has a long record of fires and serious injuries.

Our complete guide to BHO extraction covers the chemistry, history and safety in depth, and how closed-loop butane extraction works walks through the process itself.

CO₂ extraction

Carbon dioxide held above its critical temperature and pressure behaves as a supercritical fluid — it flows like a gas but dissolves like a liquid. Adjusting temperature and pressure changes what it picks up, which makes it tunable in a way most solvents are not.

CO₂ extraction commonly produces a crude oil requiring further processing — winterization, filtration, decarboxylation or distillation. Its final potency and composition depend on operating conditions and subsequent refinement rather than being inherently higher or lower than a hydrocarbon extract’s. It leaves no conventional organic-solvent residue from the primary extraction step, though downstream processing may still use ethanol. We compare the two directly in BHO or CO₂ for edibles.

Alcohol extraction

Ethanol and isopropyl alcohol have enough polarity to extract cannabinoids while also recovering chlorophyll, pigments, sugars and other polar compounds. They can co-extract waxes and lipids as well, particularly under warmer or longer extraction conditions. Chilling the alcohol materially reduces that unwanted co-extraction, which is the principle behind quick-wash techniques.

QWET (quick wash ethanol) is the better-known version and is relevant to commercial ethanol extraction. A related small-scale technique, QWISO, uses isopropyl alcohol; it is less representative of licensed commercial practice and requires complete solvent removal and credible residual-solvent testing. We cover what the cold is actually doing in quick-wash extraction.

Full-extract oils and RSO

RSO is one form of full-extract cannabis oil, or FECO, though the two terms are often used interchangeably in consumer markets. It is traditionally made by soaking cannabis in a solvent — originally naphtha, more commonly alcohol today — and removing the solvent to leave a thick, dark oil. The name comes from Rick Simpson, who popularized it in the mid-2000s after claiming he had treated his own skin cancer with it.

Because it is minimally refined compared with distillate or isolate, RSO retains a broad range of extracted plant compounds, and it is generally intended for oral or topical use rather than inhalation. The claims around it deserve careful handling: we look at what the research actually shows about RSO and cancer, and separately at what RSO is and how it is used.

Solventless separation

Solventless concentrates rely on mechanical separation, or heat and pressure, rather than dissolving the resin in an extraction solvent — so there is no extraction solvent to recover or purge afterwards.

Rosin is made by pressing cannabis, hash or kief between heated plates. Because no extraction solvent is deliberately introduced, rosin does not require the solvent-recovery and purging stages used for hydrocarbon or alcohol extracts. Its quality still depends heavily on the starting material, pressing conditions, handling and laboratory testing. Start with rosin press basics, and see how pressing conditions affect terpene retention for the part that determines flavor.

Dry sift and bubble hash separate trichome heads mechanically — with screens, or with ice water and agitation. Although water is chemically a solvent, the industry calls bubble hash solventless because the water functions as a separation medium rather than primarily dissolving the cannabinoids. We compare the two in dry sift vs bubble hash.

Solventless is not automatically safer in every respect. Contamination can arrive by other routes — see pine rosin as a contaminant for one example worth knowing about. For a direct comparison of the two families and what the chemistry actually determines, see BHO vs rosin.

What happens after primary separation

In many solvent-based processes, the initial extraction produces a crude resin or oil rather than the final product. Subsequent processing can change its composition, potency, texture, color and intended use.

• Winterization dissolves the extract in alcohol, chills the solution to precipitate waxes and lipids, then removes them by filtration.
• Decarboxylation converts acidic cannabinoids such as THCA and CBDA into THC and CBD.
• Distillation separates compounds by volatility and can produce highly concentrated cannabinoid fractions.
• Chromatography separates compounds by how differently they interact with a stationary and a mobile phase.
• Crystallization can grow THCA or CBD out of a saturated solution.
• Agitation, temperature, moisture and controlled purging — together with the extract’s own composition and how it nucleates — help determine whether a hydrocarbon extract becomes shatter, budder, wax, crumble or sugar.

This is why two products made with the same extraction solvent can look and behave completely differently — and why two products with similar textures may have reached that form by different routes.

The products you actually see on a shelf

Most names on a dispensary menu describe texture, appearance or starting material rather than a distinct extraction method.

• Shatter — a glassy, translucent form encouraged by controlled purging and minimal agitation, which help preserve an amorphous structure.
• Wax — an opaque, softer form produced when composition, agitation, temperature, moisture and other processing conditions disrupt the glassy structure associated with shatter and encourage nucleation or crystallization.
• Live resin — usually a hydrocarbon extract made from fresh-frozen rather than dried and cured cannabis, processed to retain more of the volatile profile present near harvest.
• Live rosin — rosin pressed from fresh-frozen material that has first been converted into ice-water hash, combining a “live” starting material with a solventless route.
• THCA diamonds — crystallized THCA grown out of a saturated extract, usually alongside a terpene-rich sauce.
• Distillate — a highly refined cannabinoid fraction produced by distillation after an initial extraction. Distillation is a refinement step, not an extraction method.
• Isolate — a highly purified single cannabinoid, usually CBD or THCA, produced through several stages of extraction, refinement and crystallization.
• Budder, crumble, sugar and sauce — additional finished forms created through differences in composition, crystallization, agitation, temperature and handling.

Potency is not determined by extraction method alone. A terpene-rich live resin may intentionally contain less THC than diamonds or distillate, while RSO and other full-extract oils retain a larger proportion of non-cannabinoid material by design. A batch-specific certificate of analysis is more informative than either the product name or the extraction method.

What separates a good concentrate from a bad one

Residual solvents. Any solvent-based extract must be purged, and regulated markets set limits on what may remain — though those limits and the required testing vary by jurisdiction. A certificate of analysis should report the applicable residual-solvent results alongside potency and other required contaminant testing. Products without credible, batch-specific testing warrant particular caution.

Pesticides and agricultural contaminants. Extraction can co-concentrate contaminants that share the target compounds’ solubility behavior or otherwise carry through the process. Pesticides present on the flower can end up concentrated in the extract, which is why how pesticides are removed during extraction matters more than it might seem.

Microbial contamination. Particularly relevant for solventless hash and rosin, where nothing in the process should be assumed to sterilize the material.

Heavy metals and mycotoxins. These may originate in the growing environment or the starting material, though their transfer into a finished concentrate depends on the contaminant and the process. They require direct laboratory testing rather than assumptions based on extraction method.

Potency and cannabinoid profile. Does the lab result match the label? Is it reported as THC or total THC? Is the product mostly acidic cannabinoids, or already decarboxylated?

Added ingredients. Especially relevant to vape products, where diluents, botanical terpenes or flavoring may have been introduced after extraction.

Age and storage. Heat, light and oxygen change terpene and cannabinoid composition over time. A technically excellent extract can still degrade in poor packaging.

How we got here

Concentrates are not a modern invention — charas and hashish predate every method on this page by centuries, and solvent extraction is a recent chapter in a long story. We trace it in a history of cannabis concentrates.

Originally published April 2017. Updated July 2026 to restructure the guide around the full processing chain, correct several points of solvent chemistry, and link through to our complete extraction coverage.