Cannabis Extraction: How Your Concentrates Are Made, What It Means, and Why It Matters
Cannabis concentrates have gone from a niche corner of the market to one of the most diverse and technically sophisticated product categories in the industry. Walk into a well-stocked dispensary and you'll find live rosin, distillate carts, RSO syringes, bubble hash, cured resin, FECO — and if you don't know what separates them, you're essentially shopping blind. This article breaks down how concentrates are actually made, what solvents are used and why they matter, what Oregon requires before any of it hits the shelf, and how to read the difference between products.
The fundamental split: solvent vs. solventless
Every extraction method in existence falls into one of two categories, and understanding this split is the foundation for everything else.
Solvent-based extraction uses a chemical — butane, propane, ethanol, CO2, or others — to dissolve the trichomes from the plant material. The solvent strips cannabinoids and terpenes away from the plant, then gets removed through evaporation, vacuum purging, or other processes, leaving behind a concentrated extract. The quality of the final product depends heavily on the skill of the extractor, the quality of the starting material, and how thoroughly the solvent is purged.
Solventless extraction uses no chemicals. Instead it relies entirely on physical processes — heat, pressure, agitation, cold water, and screens — to mechanically separate trichomes from the plant. Nothing is introduced that needs to be removed later. What you get is a direct physical expression of the plant material you started with.
One important distinction worth knowing: solventless and solvent-free are not the same thing. Solventless means no solvent was ever used. Solvent-free means a solvent was used but has been fully purged from the final product. Both can be clean and safe — but they are different things, and the distinction matters especially if you're a patient or someone sensitive to residual chemicals.
Solvent-based extraction methods
Butane Hash Oil (BHO)
BHO is one of the most widely used extraction methods in the commercial cannabis industry. Butane is a highly effective solvent — it's non-polar, meaning it binds selectively to cannabinoids and terpenes while leaving behind water-soluble compounds like chlorophyll. This selectivity is part of why BHO extracts can have excellent terpene profiles and very clean flavor compared to some other solvent methods.
The process runs cannabis through a closed-loop system where liquid butane passes through the plant material, dissolves the target compounds, and exits into a collection vessel. The butane is then purged — typically through a combination of heat and vacuum — leaving behind the extract. Common BHO products include shatter, wax, budder, sugar, and sauce, with the different textures resulting from variations in temperature, agitation, and moisture during the purging process.
BHO requires a licensed C1D1 (Class 1, Division 1) explosion-proof lab to produce legally and safely. Butane is extremely flammable, and amateur or uncontrolled BHO production is genuinely dangerous. In a professional, regulated setting with proper equipment, it produces some of the cleanest and most flavorful concentrates available.
Propane hash oil (PHO) works on the same principle but with propane as the solvent. Propane runs at a lower boiling point than butane, which some extractors argue preserves more volatile terpenes. Many commercial extractors use blends of butane and propane to dial in specific results.
Ethanol extraction
Ethanol is a polar solvent — meaning it binds to both fat-soluble cannabinoids and water-soluble plant compounds like chlorophyll and plant waxes. This makes it less selective than butane but also means it extracts a very broad range of compounds from the plant, which is either a feature or a drawback depending on what you're making.
Ethanol extraction at very cold temperatures (called cryogenic or cryo-ethanol extraction) significantly reduces chlorophyll pickup and preserves more of the terpene profile. At room temperature, ethanol extraction pulls more aggressively and the resulting crude requires more post-processing — winterization, filtration, and distillation — to clean up.
Ethanol is the solvent of choice for making RSO, FECO, tinctures, and the base crude that gets refined into distillate. It's FDA-recognized as a food-safe solvent, which matters for products intended for oral consumption. It's also the most scalable extraction method, which is why large-scale commercial producers rely on it heavily.
CO2 extraction
CO2 extraction uses carbon dioxide in a supercritical state — a phase between liquid and gas that occurs at specific temperature and pressure conditions — as the solvent. It's highly tunable: adjusting pressure and temperature allows extractors to target specific compounds with precision, pulling cannabinoids and terpenes separately if desired.
CO2 is non-toxic, leaves zero residual solvent in the final product by definition (it simply evaporates as a gas), and produces clean, light-colored extracts. The equipment is expensive and technically complex, and CO2 extracts are sometimes criticized for a thinner terpene profile compared to BHO or live resin, though this depends heavily on the extractor's technique. CO2 oil is very common in vape cartridges.
Solventless extraction methods
Dry sift / kief
The oldest and simplest form of concentrate. Cannabis is agitated over fine mesh screens, and the trichome heads — the resin glands that contain the majority of cannabinoids and terpenes — fall through. What's collected is kief or dry sift. Quality ranges enormously depending on screen mesh size and starting material. Full melt dry sift, made from premium material using a precise grading process, is among the most sought-after solventless products in the market.
Ice water extraction / bubble hash
Fresh or dried cannabis is agitated in ice-cold water, which causes trichomes to become brittle and break off the plant material. The mixture is filtered through a series of screens (called bubble bags or work bags) in progressively finer mesh sizes, separating trichomes by size and quality. The collected material is dried and pressed into hash.
The quality grade of bubble hash is measured by how fully it melts when dabbed — full melt, six-star hash represents the highest quality, where virtually the entire dab vaporizes cleanly with no residue. Starting material quality is everything: freeze-dried or fresh-frozen input produces dramatically better bubble hash than dried and cured flower.
Rosin
Rosin is made by applying heat and pressure to cannabis material — flower, kief, or bubble hash — using a rosin press. The trichomes rupture and the resin is squeezed out as a sap-like extract. No solvents, no chemicals, no purging required. What comes off the plates is the finished product.
Flower rosin uses dried, cured cannabis as the input. It's accessible and relatively easy to produce but yields are lower and the terpene profile, while intact, reflects the cured material. Hash rosin — made by pressing high-quality bubble hash rather than flower — is the premium tier of solventless production. The starting material is already concentrated, so the resulting rosin is purer, more flavorful, and represents the cleanest expression of the plant's full chemical profile. Live rosin uses fresh-frozen input material, preserving the volatile terpenes that are lost during drying and curing.
Hash rosin pressed from quality six-star bubble is the product that serious concentrate consumers tend to point to as the ceiling of what cannabis extraction can produce. The price reflects that.
Specific products and what makes them different
Live resin
Made from cannabis that is flash-frozen immediately after harvest — before any drying or curing — live resin captures the plant's full terpene profile at its peak. Drying and curing causes significant terpene loss. Freezing stops that process cold. Live resin is typically produced using BHO or CO2 and results in an extract that's closer to what the living plant actually smelled and tasted like. Widely considered a benchmark for flavor in solvent-based concentrates.
Cured resin
The same solvent-based extraction process as live resin, but using dried and cured starting material. The terpene profile is more muted than live resin, but quality cured resin from good starting material is still significantly more complex than distillate. It sits in the middle of the market — more affordable than live, more interesting than distillate.
Distillate
The result of taking an ethanol or BHO crude extract and running it through short-path or wiped-film distillation — a process that separates cannabinoids by their boiling points. The output is an extremely refined, nearly colorless oil that's typically 80–95% THC or CBD with almost nothing else present. Terpenes, minor cannabinoids, waxes, chlorophyll — all of it is stripped away.
Distillate is the dominant format for vape cartridges because it's stable, consistent, and fills carts cleanly. Because it has no flavor of its own, virtually all distillate carts have terpenes added back in post-production — either cannabis-derived terpenes (CDT) or botanical terpenes from non-cannabis sources. CDT carts are generally considered more authentic. The quality of those added terpenes varies enormously between brands, which is why two distillate carts at the same THC percentage can taste and feel completely different.
RSO (Rick Simpson Oil)
Named after Canadian cannabis advocate Rick Simpson, who popularized a high-potency whole-plant cannabis oil in the mid-2000s. RSO is a full-spectrum, whole-plant extract traditionally made using isopropyl alcohol or naphtha as the solvent — both more aggressive than ethanol. The solvent is boiled off at higher temperatures, which purges it from the final product but also drives off volatile terpenes in the process. The result is a thick, dark, tar-like oil with very high cannabinoid content and a raw, earthy character.
RSO gained significant attention through anecdotal reports of use by cancer patients and people with serious chronic conditions. The research base for its specific therapeutic claims is still limited, but it remains one of the most potent and accessible whole-plant products on the market.
Important: because RSO was historically a DIY product and the solvent profile varies, always verify the COA (certificate of analysis) on any retail RSO to confirm what solvent was used and that residual levels are within Oregon's legal limits.
FECO (Full Extract Cannabis Oil)
FECO is functionally similar to RSO — a whole-plant, full-spectrum, high-potency oil in a syringe — but produced using food-grade ethanol rather than isopropyl alcohol or naphtha. The lower processing temperature preserves more of the plant's terpene profile, and ethanol is an FDA-recognized food-safe solvent, making FECO the cleaner and more consumer-friendly version of the concept.
A single gram syringe of FECO can contain 600–800mg of THC — the equivalent of 60 to 80 standard edible doses. Start with a rice-grain-sized amount and go from there. These products are not casual.
In a licensed Oregon dispensary, both RSO and FECO on the shelf have been tested and cleared through the state's testing requirements. The distinction between them is mainly solvent choice and processing temperature, which affects the terpene profile and the feel of the product.
What Oregon requires before it reaches the shelf
Oregon has some of the most comprehensive cannabis testing requirements in the country, administered jointly by the OLCC and OHA. Every concentrate and extract sold in a licensed dispensary has been tested and passed for all of the following:
Potency — cannabinoid percentages including THC, CBD, and in many cases minor cannabinoids. Required for all products.
Pesticides — Oregon requires testing against 59 specific pesticides. For some compounds like myclobutanil, zero detectable levels are allowed. No exceptions.
Residual solvents — any product made using a chemical solvent must pass solvent testing. Oregon sets specific action levels: butane and propane must be below 800 ppm. Processors using only mechanical extraction or water, animal fat, or vegetable oil are exempt from solvent testing. Solventless products — rosin, bubble hash, dry sift — skip this test entirely because there's nothing to test for.
Heavy metals — required for all concentrates and extracts manufactured on or after March 1, 2023.
Mycotoxins — required for products manufactured on or after July 1, 2022. Mycotoxins are toxic compounds produced by molds, and their presence in a product that's going to be inhaled is a serious health concern.
Microbiological contaminants — required for products manufactured on or after March 1, 2023. This covers mold, yeast, bacteria, and other biological contaminants.
All testing is performed by third-party ORELAP-accredited labs — labs that are independently certified and not affiliated with the producers they test. A batch that fails any of these tests cannot be sold. The test results are logged in METRC, Oregon's seed-to-sale tracking system, which means the chain of custody is documented from harvest to sale.
When you see a COA — certificate of analysis — attached to a product, it's a direct readout of those lab results. Any reputable producer or dispensary will make COAs available on request. If a brand won't show you their COA, that tells you something.
How to read what you're buying
A few things worth checking on any concentrate purchase:
COA date — testing is batch-specific. A COA from a year ago on a product that's been sitting around doesn't tell you much. Look for recent test dates.
Solvent used — for solvent-based products, check whether the COA lists the solvent and whether residuals are below action levels. Reputable producers show this clearly.
Terpene profile — not all labs test for terpenes, and it's not required by Oregon law. But producers who are proud of their terpene work often include it voluntarily. If you see it, use it — it tells you more about the experience than THC percentage alone.
Live vs. cured vs. distillate — this should be labeled clearly. If a cart just says "cannabis oil" without specifying, it's almost certainly distillate.
CDT vs. botanical terpenes — for distillate carts specifically, whether the added terpenes are cannabis-derived or botanical matters to many consumers. It should be on the label.
The concentrate market rewards people who ask questions. Our budtenders know this stuff in depth — come in and ask what's worth your money this week.
Sources
Oregon Health Authority / OLCC — OAR 333-007-0341, 333-007-0400, 333-007-0410, 333-007-0415, 333-007-0425 — Oregon Concentrate and Extract Testing Requirements
SC Labs Oregon — Oregon Cannabis Compliance Testing Overview
Harris Bricken / Canna Law Blog (2023) — Oregon Cannabis: Challenging Testing Requirements Take Effect March 1, 2023
King Harvest (2025) — FECO vs RSO: 2025 Comparison Update
Rootsciences.com (2026) — Cannabis Extraction: Common Methods Explained
MJBizDaily (2025) — Cannabis Extraction Debate: Solvents Versus Solventless Methods
Low Temp Plates — Solventless Extraction 101: Comprehensive Guide
