CBD extraction methods compared: CO2, ethanol and solventless

By Manon, CBD specialist at Deli Hemp Pro

Updated 22 October 2026.

CBD flower is not extracted: it is sold as it is, dried and trimmed. Extraction is used to make other things from the plant: isolates, distillates, concentrates such as crumble, and some resins. Each method yields a particular type of product, with its own points to check.

Here are the five methods you will come across on suppliers' product sheets, what they produce and what to ask before you buy.

How does supercritical CO2 extraction work?

Carbon dioxide, at high pressure and controlled temperature, is passed through the plant material. In this “supercritical” state, CO2 dissolves the cannabinoids and terpenes, then turns back into a gas when the pressure drops and evaporates without leaving any residue.

It is the cleanest and most adjustable method: by changing the pressure, you can target certain compounds. On the other hand, it needs expensive equipment and gives lower yields on small volumes. It is the typical method for extracts intended for cosmetics and for premium raw materials.

What about ethanol extraction?

The material is soaked in ethanol, which dissolves the cannabinoids, and the alcohol is then evaporated. The method is efficient and suited to large volumes, but ethanol also pulls out chlorophyll and waxes. A “winterisation” step (chilling, then filtering) is needed to remove them, plus a check for residual solvent.

What do hydrocarbon extractions produce?

Butane or propane, used in a closed loop, preserve terpenes particularly well. This is the usual route for concentrates with a distinctive texture: crumble, shatter, budder. These solvents are flammable and require professional facilities. For a retailer, the key question is the purge: the finished product must be free of solvent, and only a residual solvent test proves it.

We look at this kind of product in our article on CBD crumble.

What happens to these crude extracts?

Whatever the method, the crude extract then goes through refining steps that decide the final product:

• Distillation separates the cannabinoids from other compounds and gives a distillate, a thick oil at around 90% CBD (€0.65 per gram excl. VAT in bulk).
• Crystallisation isolates CBD on its own and gives a powdered isolate at 99.8% (€0.325 per gram excl. VAT in bulk).
• Vacuum purging of a hydrocarbon extract gives a concentrate such as our Crumble 85% CBD (€0.70 per gram excl. VAT in bulk).

Solventless methods: dry sift, ice-o-lator, rosin

Here nothing is dissolved: the trichomes, the plant's resin glands, are separated mechanically. Dry sift sieves them dry, Ice-O-Lator knocks them off in ice-cold water, and Frozen Sift sieves them from frozen material. Rosin presses plant material or resin between two heated plates to squeeze out an oil.

These methods give resins and hash, not isolates. Their commercial advantage: no solvent to check, and a texture and aroma close to the plant. We compare them in detail, with prices, in our guide to Frozen Sift, Dry Sift and Ice-O-Lator.

Comparison table

What really matters for a retailer

The extraction method alone does not guarantee quality: a good CO2 extract badly refined gives a mediocre product, and a well-dried ice-o-lator an excellent one. Two rules apply to every method. First, extraction concentrates THC as well, so an extract must be checked batch by batch, with delta-9-THC below 0.3%. Second, any method that uses solvent must be able to prove there are no residues.

Batch reports can be downloaded from the product pages that have one; for the others, ask for them before you order. To read these documents line by line, see our guide to the certificate of analysis. Our products comply with French law (delta-9-THC no higher than 0.3%). The rules for reselling hemp products differ from one country to the next, and the status of hemp flower and resin in the UK remains contested: check what you may sell locally before you order.

Frequently asked questions

What is the best CBD extraction method?

There is no single best one: each method serves a product. CO2 suits clean raw materials, ethanol large volumes, hydrocarbons aromatic concentrates, and solventless methods resins. Quality depends above all on the starting material and the refining that follows.

Is CBD flower extracted?

No. The flower sold in shops is simply grown, dried and trimmed. Extraction applies to plant material destined to become isolate, distillate, concentrate or resin. The growing method (indoor, greenhouse, outdoor) has nothing to do with extraction.

Does an isolate contain THC?

A well-crystallised isolate contains almost nothing but CBD, at over 99%. You still need to read the batch report: it shows whether THC is not detected or present below the 0.3% limit applied in France.