How CBD oil is made: 8 steps from field to bottle

Oils vary in the details, yet they share one outline: prepare the plant, extract the cannabinoids, purify the extract, decarboxylate it, dilute it, test it. The diagram follows that sequence. Some workshops decarboxylate before extraction, on the ground flower; others do it afterwards, on the extract.

The process begins with the plant. In France, the decree of 30 December 2021 only allows Cannabis sativa L. varieties listed in the EU common catalogue or the French catalogue whose Δ⁹-THC content does not exceed 0.30%. Extracts and the products that contain them, the finished oil included, are held to the same threshold.

After harvest, the flowers are dried and then ground. Grinding exposes the trichomes, the tiny glands where the plant stores its cannabinoids. A 2021 review in the Journal of Cannabis Research describes traditional hang-drying at 18 to 25 °C with 45 to 55% humidity. Freeze-drying uses cold and vacuum instead. It keeps more of the volatile compounds and consumes a lot of energy.

Extraction pulls the cannabinoids and terpenes out of the plant material. Three families of solvents dominate, each with its own compromise.

Past its critical point, CO₂ moves through the material like a gas and dissolves compounds like a liquid. Once the pressure drops back to ambient, it reverts to gas and escapes. The 2021 review cites working conditions of about 55 °C and 34 MPa, or 340 bar, with a little ethanol as a co-solvent. The settings are covered in our article on supercritical CO₂ extraction.

Ethanol is among the solvents with the best cannabinoid yields. It also takes chlorophyll with it, which is then filtered out through activated charcoal, and some cannabinoids are lost on the way. The review raises two problems with the hydrocarbons, butane and propane: they are flammable, and industrial-grade solvents can leave impurities in the extract. To spot them on a certificate, see the guide can a CBD hash contain solvents.

Plant waxes and lipids in the raw extract would make the oil cloudy, and winterisation takes them out. The extract is dissolved in ethanol and chilled well below zero, so the waxes solidify and settle while the cannabinoids stay in solution. A cold filtration separates the two. The ethanol is then evaporated, often under vacuum, which allows a lower working temperature.

Some solvent always remains. The ICH Q3C guideline, applied by the European Medicines Agency to medicines, puts ethanol in class 3, the least toxic solvents. It accepts up to 5,000 ppm of this kind of solvent, or 0.5% with no specific justification needed. A CBD oil is not a medicine. Still, the threshold gives you a sense of scale when you read the "residual solvents" line on a certificate.

Very little CBD comes straight from the plant. It makes CBDA, the acidic form, and heat strips off a carboxyl group to give CBD. A 2016 study tracked this reaction between 80 and 145 °C, over 60 minutes at most and found that conversion speeds up as the temperature rises. The authors also saw the combined CBDA and CBD fall as time and temperature increased. Heat applied too hard or too long costs cannabinoids.

Losing that carboxyl group takes about 12% off the molecule's mass. Total CBD in an oil is therefore estimated as: total CBD = CBD + 0.877 × CBDA. Take the catalogue's 10% CBD Oil, checked on 23 September 2026: batch PG-26-8C8F shows 10.2% CBD and 0.4% CBDA, which gives about 10.55% total CBD. The catalogue's three oils show 0.2 to 0.4% CBDA, so decarboxylation on these batches is incomplete. Our guide to decarboxylation compares the methods.

Once decarboxylated, the extract is too concentrated to dose directly. It goes into a carrier oil: often a medium-chain triglyceride (MCT) oil from coconut, sometimes hemp seed or olive oil. The label tells you which.

A rule of three does the job. A 100 g bottle at 10% CBD needs 10 g of CBD. Take a purified extract at 60% CBD, a figure picked for the example: you need 10 ÷ 0.60 = 16.7 g of it, plus 83.3 g of carrier oil. A 99% isolate would need only 10.1 g. Extract purity also tells you what else is in the bottle. A 60% extract adds other cannabinoids and terpenes, while an isolate adds CBD and nothing more.

Our articles on full spectrum and on 99% isolate define these terms. All three oils in the catalogue's CBD oils category are full spectrum: 5.1% CBD for the Full Spectrum, 10.2% for the 10% CBD Oil and 19.6% for the product called "10". Their Δ⁹-THC ranges from 0.1 to 0.2% depending on the batch. On 23 September 2026, prices started at €29.90.

Dilution and mixing are never perfect, so the calculated percentage has to be confirmed on the finished batch. A useful certificate of analysis has at least five lines:

1. the CBD content, as a percentage or in mg/ml, and any CBDA left;
2. the Δ⁹-THC, which must not exceed 0.30%;
3. residual solvents, if a solvent was used for extraction;
4. pesticide and heavy-metal results;
5. the batch number, identical to the one printed on the bottle.

A good certificate also looks for the semi-synthetic molecules classified as narcotics in France, such as HHC, H4CBD or THCP. Each line is explained in our guide to the certificate of analysis, and the laboratory page describes the measurement methods.

The way an oil is made does not decide how it may be used. A CBD oil meant to be swallowed is a food, and the Regulation (EU) 2015/2283 on novel foods requires an authorisation that no CBD ingredient has obtained. On 20 May 2026, the French Ministry of Agriculture restated its view that foods containing CBD are illegal and must be withdrawn from the market, food supplements included. The ministry also reports a rise in poisoning reports linked to these products since 2024. What is still on sale is described in our update on CBD regulation in 2026.