CBD extraction is the step that turns hemp into an extract: a solvent dissolves cannabidiol (CBD) and other plant compounds out of the flowers. Every cannabidiol extraction from cannabis works this way, and the common CBD extraction methods use CO2, ethanol or plant oil as the solvent. Hemp here means cannabis with under 1% THC.
Purification follows, and only then does a carrier oil turn the extract into CBD oil, so CBD oil extraction is really extraction plus blending. “CBD extraction” and “how CBD is made” name one process from two angles.
The extraction method is an attribute you can check on the product page and in the lab report. We show you what of it you can recognise on the finished product.
Important Notice: CBD products are not medicines and do not replace medical treatment in any way. They are not intended to diagnose, treat, or cure any disease. Always consult your doctor before using CBD, especially if you are taking other medications. The information in this article is provided for educational purposes only and does not constitute medical advice. CBD oils sold by uWeed are not intended for ingestion: please read the package instructions carefully and follow all warnings provided.
What is CBD extraction?
CBD extraction is a separation process in which a solvent dissolves cannabidiol (CBD), other cannabinoids and terpenes out of the flowers and leaves of the cannabis plant. In Switzerland the raw material is hemp with under 1% THC. The result is a crude extract: a dark, resinous concentrate of these compounds that is not yet CBD oil.
How is CBD extracted? The cannabinoids sit in the resin of the trichomes, the tiny resin glands on hemp flowers, and in the living plant cannabidiol is mostly present as its acid form, CBDA. To extract CBD from hemp, manufacturers choose a solvent in which this resin dissolves: CO2, ethanol or plant oil, depending on the method.
Extraction is dissolving, not pressing. Hemp seed oil, by contrast, is cold-pressed from the seeds and is a culinary oil, a different product altogether. Cannabis extraction is the broader term for the same dissolving step, and every cannabidiol extraction from cannabis first yields this crude extract. “Cannabis oil” in everyday speech usually means something else again: an extract with far more THC than Swiss hemp may contain.
How is CBD oil made?
CBD oil is made in six steps, from harvested hemp to the filled bottle, and the CBD extraction process is only one of them. Each step leaves a trace on the product.
- Harvest and drying: the hemp flowers are harvested and dried.
- Decarboxylation: heat converts the acid form CBDA into CBD.
- Extraction: CO2, ethanol or plant oil dissolve the cannabinoids into a crude extract.
- Winterisation and filtration: cold and filters remove waxes and chlorophyll.
- Distillation: under vacuum, the cannabinoids of the extract are concentrated.
- Blending: extract and carrier oil become CBD oil, then the batch is analysed in a laboratory.
The order of steps 2 and 3 varies by manufacturer. The answer to how to extract CBD sits in step 3, and how CBD is made beyond that is decided in steps 4 and 5; the next two sections cover both. Step 6 is the one you see on the product itself: with Swiss CBD oil and CBD extract, the declared concentration and the carrier oil are listed in the product details.
What are the most common CBD extraction methods used today?
The most common CBD extraction methods today are CO2 and ethanol extraction, alongside oil infusion and, for concentrates, butane. They differ above all in the solvent, and temperature, co-extracted compounds and the purification needed all follow from it. Ordered by solvent, they run from a gas under pressure (CO2) through alcohol (ethanol) and plant oil to hydrocarbons (butane, propane). Ultrasound comes last: it is an aid combined with ethanol or oil, not a solvent of its own, so it has no column in the table.
| Criterion | CO2 | Ethanol | Plant oil | Butane and propane |
|---|---|---|---|---|
| Solvent | carbon dioxide under pressure | alcohol | olive oil, MCT oil or hemp seed oil | liquefied gas |
| Temperature range | low to medium | low to medium | medium | low |
| Co-extracted compounds | few, adjustable | many: chlorophyll and waxes | many, they stay in the oil | few |
| Purification needed | medium | high | none, the infusion stays as it is | high, the gas must be removed completely |
| Residual solvents on the lab report | not applicable, CO2 leaves as a gas | ethanol, where tested | not applicable, the oil stays as carrier oil | butane and propane, where tested |
| Typical end product | extract for CBD oil | extract for CBD oil | low-concentration infused oil | concentrate |
Temperature is the lever all methods share: the cooler the process, the more terpenes survive in the extract. Three takeaways from the comparison:
- CO2: the solvent leaves as a gas after extraction; in return, the equipment is costly.
- Ethanol: alcohol dissolves a lot, so the extract needs more purification.
- Butane and propane: a process for concentrates that belongs in closed industrial systems only.
So what is the best extraction method for CBD? None is, across the board: each suits a different product, and the solvent decides how much purification follows. Solvent-free processes such as pressing, sieving or ice-water separation give other products, not an extract for CBD oil, and none of the CBD oils in our range lists cold pressing as its extraction method.
1. Supercritical CO2 extraction of CBD
CBD CO2 extraction uses supercritical carbon dioxide as the solvent. Above its critical point, at around 31 °C and 74 bar, carbon dioxide behaves like a gas and a liquid at once; in that state it passes through the plant material and dissolves cannabinoids and terpenes out of it. Pressure-resistant equipment makes supercritical CO2 extraction an industrial process.
Pressure and temperature steer what dissolves. Below the critical point the system runs subcritical, with liquid rather than supercritical CO2: cooler and at lower pressure, more terpenes are kept while the yield falls. For a terpene-rich CO2 extract that is the craft trade-off, more hemp aroma for less volume, and what terpenes in cannabis are and how they shape that aroma has a guide of its own.
Once the work is done, the pressure is released: the carbon dioxide turns back into a gas, separates from the extract in the separator and is fed back into the loop. That CO2 leaves the extract as a gas is a property of the process, and the CO2 extract is then usually winterised. On a CO2-extracted oil, “CO2 extraction” is stated in the product details, and across our range it is the method named most often. The statement tells you the solvent; the spectrum is decided by the purification that follows.
2. Ethanol extraction of CBD
Ethanol CBD extraction relies on alcohol as a polar solvent, which dissolves CBD, other cannabinoids and terpenes, and also chlorophyll and plant waxes that nobody wants in the extract. Before filtration the crude extract is therefore dark green and smells strongly of hemp.
Temperature decides how selective ethanol is. Run cold, alcohol dissolves fewer of these unwanted compounds; run warm, it works faster. The alcohol is then evaporated and recovered for reuse, and the extract is winterised and filtered, which is why purification is always part of an ethanol extraction.
In the product details you then read “ethanol” as the extraction method, and on the lab report ethanol appears under residual solvents, where that value was tested. What is meant is always industrial extraction in closed systems, never steeping plant material at home.
3. Oil infusion with olive oil and other plant oils
Oil infusion is the simplest extraction method and the one with the lowest concentration. Cannabinoids are fat-soluble, so decarboxylated plant material is steeped in warmed plant oil (olive oil, MCT oil or hemp seed oil) in a process called maceration. The oil is solvent and carrier oil at once and is never separated off: it is the only solvent that stays in the product.
An infused oil cannot be concentrated, so high percentages are hardly reachable this way. That makes oil infusion the method of home makers, while manufacturers usually dissolve a concentrated extract in the carrier oil instead; the section on making CBD oil at home picks this up. The carrier oils you will see in the product details include coconut oil (MCT), hemp seed oil and olive oil.
4. Butane extraction (BHO)
BHO stands for butane hash oil: liquefied butane or propane is used as the solvent for cannabinoids and terpenes. The result is a solid to waxy concentrate, not an extract that becomes CBD oil in a carrier oil, so butane as a solvent for concentrates belongs to a different product category.
Extraction runs in closed loops, and the gas must be removed completely afterwards; industrially, solvent residues are removed under vacuum in a vacuum oven. Without vacuum equipment the residues cannot be driven out in a controlled way, which is why the method belongs in closed industrial systems only.
Butane is highly flammable: at home, this method is life-threatening because of the explosion risk.
5. Ultrasonic extraction
Ultrasonic extraction uses ultrasonic waves to create cavitation in a solvent: microbubbles form and collapse, breaking open the cell walls so that cannabinoids go into solution faster without strong heating. Ultrasound therefore only speeds up the extraction. It is an aid combined with ethanol or oil, and the solvent stays the same.
At industrial scale, ultrasound-assisted extraction is less widespread than CO2 and ethanol. Even so, “ultrasonic” appears as the method in the product details of individual oils. In our range, the Alpsbee CBD oils, for example, name ultrasonic extraction as their process.
Purifying the hemp extract after extraction
The crude extract is dark and waxy: besides cannabinoids it holds waxes, fats and chlorophyll. Purification decides whether it becomes a full-spectrum extract, a distillate or an isolate. Four steps lead from crude extract to isolate, not all of them for every end product: decarboxylation, winterisation with filtration, distillation and crystallisation.
The further the extract is purified, the lighter it gets and the fewer other plant compounds it holds.
Decarboxylation from CBDA to CBD
Decarboxylation converts the acid form CBDA into CBD with heat: the carboxyl group splits off as carbon dioxide. “Activation”, the word you may read for this step, is meant chemically and says no more than that. In the plant, cannabidiol is present as cannabidiolic acid, and only heat turns it into CBD.
The step is done on the dried plant material before extraction, or afterwards on the extract; some manufacturers decarboxylate in the oil. In industry, decarboxylating cannabis means running temperature and time so that as much CBDA as possible converts and as little CBD as possible breaks down. On the product, “decarboxylated” stands for the golden rather than the dark stage. Too much heat breaks cannabinoids down again, which the section on the boiling point picks up.
Winterisation and filtration
Winterisation is cold used as a separation method: the extract is dissolved in ethanol and chilled hard, and co-extracted waxes and fats drop out. Whatever turns solid in the cold stays in the filter. Filtration separates these waxes and fats off, and activated carbon can additionally bind chlorophyll. Winterisation comes before distillation, so these lipids do not travel into the next step.
You can see the result: a cloudy, thick crude extract becomes a clearer, thinner extract that does not cloud the carrier oil. After ethanol extraction the step is a fixed part of the process; after CO2 extraction it is usual. Where it is listed, you find the result in the product details as the filtration stage.
Distillation from crude extract to distillate
Distilling CBD means heating the extract until the cannabinoids vaporise and collecting the vapour separately. Distillation separates by boiling point, and because cannabinoids tolerate heat badly, it is done under vacuum: the boiling point falls, the extract is distilled at a lower temperature and less cannabidiol breaks down. The figure itself is in the section on the cannabidiol boiling point below.
Short-path and molecular distillation are the common designs, and the distillate is collected in fractions, first the volatile terpenes, then the cannabinoids. The result is a light, clear CBD distillate with a high share of cannabinoids, in which terpenes are largely missing. On the product, “distilled” is the clear stage, and broad-spectrum extracts and isolate usually build on the distillate.
Crystallisation from distillate to CBD isolate
To extract CBD isolate, manufacturers dissolve the distillate in a solvent and cool it until cannabidiol crystallises out. The crystals are separated, washed and dried. This is the end point of purification: the distillate is refined until only cannabidiol is left to crystallise.
The result is CBD isolate as a white, almost odourless powder or crystal. It no longer holds terpenes or other cannabinoids, and its CBD share is the value the lab report states for the individual product. At uWeed, CBD crystals and CBD isolate have a category of their own.
What does the extraction method tell you about a CBD oil?
The extraction method tells you which solvent and how much purification stand behind a CBD oil, and with that, which plant compounds stayed in the extract. It is an attribute, not a quality mark. You can read how an oil was made in three places: its spectrum, the stated extraction method and the lab report.
Colour is the rule of thumb: dark is raw, golden is decarboxylated, clear is distilled. The less an extract was purified, the deeper its colour and the stronger its hemp aroma.
The next two sections show what the spectrum says about purification and where you find these statements on the product.
Full spectrum, broad spectrum and isolate as stages of purification
Full spectrum, broad spectrum and isolate are three stopping points of the same process: how far the extract is purified decides the spectrum. The least purified is the full-spectrum extract, which keeps the plant’s cannabinoid profile and terpenes after winterisation, with under 1% THC. In the shop you find it as full-spectrum CBD oil.
In a broad-spectrum extract, one more step separates off most of the THC. At the end of the line stands CBD isolate, which contains cannabidiol only. The more plant compounds you want in the oil, the earlier the stopping point, and the middle one has its own category as broad-spectrum CBD oil.
The extraction method on the label and the lab report
What a manufacturer says about extraction can be checked in two places: the product details and the lab report. Between them they show the method, the spectrum and what the batch actually contains. What you can check:
- Product details or label: the extraction method, such as CO2 extraction, ethanol or ultrasonic
- Spectrum and filtration stage: raw, decarboxylated or distilled
- Lab report (certificate of analysis, CoA): the cannabinoid profile with the CBD and THC content of the batch
- Residual solvents on the lab report: where tested, a line of its own and the check on the method
Not every report covers every parameter, and where a brand supplies no report, we say so on the product page. The percentage on the bottle is the CBD content the lab report states for that batch, and the THC value is read against the Swiss limit of under 1% THC, not a foreign one.
CBD extraction in Switzerland and the limit of under 1% THC
In Switzerland, keeping to the THC limit is the manufacturer’s real task in CBD extraction, because the limit applies to more than the plant. Hemp and hemp preparations with a total THC content under 1% are not narcotics; from 1%, the Swiss Narcotics Act (BetmG, SR 812.121) applies. This is the Swiss limit, and other countries set other limits, so a figure quoted on a foreign page does not apply here.
| Attribute | Value |
|---|---|
| Country | Switzerland |
| Limit | under 1% total THC |
| Applies to | hemp and hemp preparations; for cosmetics also every intermediate product of manufacture |
Extraction concentrates all cannabinoids, including the traces of THC in the hemp. Whether the solvent is CO2 or ethanol, the manufacturer has to run the process so that no intermediate product crosses the limit, for example by diluting the extract in the carrier oil or by separating off THC. The lab report states the THC content of the batch.
The limit is a legal fact, not a quality argument. In broad-spectrum extracts, THC is additionally separated off in a step of its own. You find the framework in detail in our guide to the legal status of CBD in Switzerland.
Can you make CBD oil at home?
Yes, but only in one form: an oil infusion is the one method that works without industrial equipment, while CO2 extraction, distillation and butane need closed industrial systems. A home-made CBD-infused oil stays low in concentration, and nobody has measured it: without a lab analysis, its CBD content and its THC content stay unknown.
That is the real limit of any answer to how to make CBD-infused oil. There is no batch, no lab report and no stated percentage, so you cannot know how much cannabidiol the oil holds. The same goes for THC: whether a home-made oil stays under 1% THC is not something you can check at home.
Butane is a different matter altogether, and at home it is life-threatening because of the explosion risk. On a bought oil, by contrast, the lab report states both values for the batch, the CBD content and the THC content, and that is the difference that counts when you compare.
Cannabidiol boiling point and degradation by heat, light and oxygen
The boiling point of cannabidiol depends on the pressure: the Merck Index gives 187–190 °C at 2 mmHg, a strongly reduced pressure. Long before it boils, heat starts to break cannabidiol down, which is why manufacturers distil under vacuum.
| Attribute | Value | Note |
|---|---|---|
| Boiling point of cannabidiol | 187–190 °C | at 2 mmHg (about 2.7 mbar), per the Merck Index |
Degradation here means the chemical breakdown of the molecule in the extract, not metabolism in the body. Heat, UV light and oxygen are the three drivers: oxygen oxidises cannabidiol, while heat and light speed the breakdown up. In the process, manufacturers counter them with low temperatures, vacuum and inert gas.
What holds in the process holds in the bottle: the CBD content falls over time, faster with warmth, light and an open cap. Look for amber glass, which protects against UV light, and a tight closure. Storage itself is covered in our guide to the shelf life of CBD oil.
Frequently asked questions about CBD extraction and processing
Two questions about CBD extraction come up again and again when you read a product page and a lab report.
Do solvents remain in CBD oil after extraction?
Whether solvents remain in CBD oil after extraction depends on the method, and it is measured in the laboratory. CO2 leaves the extract as a gas, ethanol is evaporated and butane is removed under vacuum. Whether residues remain is shown by the residual-solvents line on the lab report, where it was tested. So open the report on the product page and look for that line; if it is missing, the value was not determined in that analysis.
Is CO2-extracted CBD oil automatically organic?
No, CO2-extracted CBD oil is not automatically organic. “Organic” describes how the hemp was grown and a certification, while “CO2 extraction” describes the method. An oil can be CO2-extracted and not organic, and the other way round. What counts is the organic attribute stated on the individual product, so check the product details for the two statements separately: once for the extraction method, once for “organic”.
The bottom line on CBD extraction
CBD extraction means a solvent dissolves cannabinoids out of hemp. For CBD oil, CO2 and ethanol are the common methods, and the difference between them lies in the purification needed, not in a ranking. Purification then decides the spectrum, from full spectrum through broad spectrum to isolate.
