Short answer
Solventless (heat and pressure, such as a rosin press) uses no chemical solvent and keeps material fresh, but recovers fewer cannabinoids and suits small batches. Ethanol is widely available, quick and easy to run, but means storing a lot of solvent and managing residues. CO2 has the highest equipment cost but, according to extraction chemist Dr. Jon, the lowest operating cost per gram and no solvent residue. The right method depends on your volume, budget, local rules and the product you want to make.
| Solventless | Ethanol | CO2 | |
|---|---|---|---|
| How it works | Heat, pressure or mechanical separation (e.g. a rosin press) | Plant material is washed in ethanol, which is then removed | Pressurised carbon dioxide acts as the solvent, then returns to a gas |
| Equipment cost | Low to moderate | Moderate | Highest; Dr. Jon puts it at up to about double ethanol equipment |
| Running cost | Low, but low recovery | High, in Dr. Jon’s view (solvent and facility costs) | Lowest per gram, in Dr. Jon’s view |
| Residual solvent | None (no solvent used) | Possible, especially with denatured ethanol | None left once the CO2 is removed |
| Scale | Small, artisan batches | Small to large | Small to large; modern systems are more compact |
Dr. Jon describes the rosin press as the typical solventless setup: two heated plates press the plant material, live or dried, so the resin melts and runs out onto parchment paper. The advantage is a very fresh extract with no chemicals touching it. The disadvantage, in his words, is that recovery is poor: much of the cannabinoid content stays in the plant, and a rosin press is not a tool for processing large volumes of hemp.
His key safety point: get a certificate of analysis (COA) for pesticides and heavy metals on the input material before you press it, especially fresh material. With no solvent step there is nothing in the process that removes those contaminants.
Ethanol is popular because it is easy to get, quick and simple to use. Dr. Jon names three trade-offs. First, residues: food-grade ethanol is expensive, so many operators use denatured ethanol, and its denaturants can remain as contaminants. Second, the facility: storing large volumes of flammable solvent has to meet fire and building codes, which costs money. Third, operating cost, which he says is far higher per gram than CO2.
His advice applies to every method: compare capital cost and operating cost before you buy. If you only look at the purchase price, your extract can end up costing more to make than competitors’.
For CO2, Dr. Jon puts the main drawback up front: equipment costs more, up to about double an ethanol setup. In his view the operating cost is the lowest of the three, so the difference can be recovered within months of steady operation. Because pure CO2 returns to a gas when it is removed, there is no solvent left in the extract. He adds that older complaints about CO2 systems, such as high power use, large footprints and low throughput, are less true of current equipment.
Dr. Jon’s ethanol and CO2 comparisons come from a chemist who works with extraction equipment, so treat the cost figures as one maker’s view and get your own quotes.
Butane and propane extraction is a fourth common method, mostly used for cannabis concentrates. Like ethanol, it involves flammable solvents, residual-solvent testing and strict facility rules. Our guide to butane hash oil (BHO) covers it, and hot and cold extraction methods covers small-scale techniques.
There is no single best method. Solventless suits small, artisan batches and avoids solvents but recovers less. Ethanol is fast and easy to run but brings solvent storage and residue concerns. CO2 costs the most to buy but, in Dr. Jon’s view, the least to run and leaves no solvent behind. Volume, budget, local rules and your end product decide.
It depends on what you are optimizing for. Dr. Jon says CO2 equipment can cost up to about twice as much as ethanol equipment, but that CO2 is cheaper to operate and leaves no residual solvent. Ethanol is quicker to get started with. These are the views of one chemist who works with extraction equipment, so compare quotes and operating costs yourself.
Solventless extraction separates resin from the plant with heat, pressure or mechanical methods instead of a chemical solvent. A rosin press, for example, squeezes material between two heated plates so the resin melts and runs out onto parchment.
It can. Dr. Jon points to denatured ethanol in particular: the denaturants added to it can remain as contaminants in the extract. Finished products are tested for residual solvents under state rules.
Solventless and ethanol setups usually cost less to buy than CO2 systems. Dr. Jon’s point is that purchase price is only half the picture: count operating cost per gram over time, plus the facility work needed to store solvents safely.
Yes. Rosin is made with heat and pressure and no chemical solvent, which is why it is grouped with solventless methods.
Learn extraction from a PhD chemist, not a textbook. Dr. Jon’s full set of interview segments, from biomass preparation to isolate and residual-solvent testing, is part of the Cannabis Extraction Certificate. Or start with the free 10 Tips to Get Started in Extraction.
More in Cannabis 101
Check your state's cannabis laws
IACET Accredited Provider · online cannabis education
Since 2009 • 50,000+ students trained worldwide
Copyright Cannabis Training University, a subsidiary of Online Training Providers. © 2026. All Rights Reserved.
Medical Disclaimer: The information on this website is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment.
Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition.
Legal Compliance: Cannabis remains federally illegal. Products and information are intended only for jurisdictions where cannabis use and possession is legal.
By using this site, you affirm that you are of legal age (21+) and responsible for understanding your local laws.
