What is solventless?
Solventless concentrates are made using only physical force — water, ice, heat, and pressure — never chemical solvents like butane, propane, CO₂, or ethanol.
The two families of concentrates
Cannabis concentrates split into two camps. Solvent-based extracts (BHO, PHO, CO₂ oil, distillate) use a chemical solvent to dissolve cannabinoids and terpenes from plant material, then purge the solvent off. Solventless extracts (hash, rosin, kief) physically separate the trichome heads — the resin glands that hold THC, CBD and terpenes — without ever introducing a foreign substance.
Why it matters
Even a perfectly purged BHO contains trace residual hydrocarbons measured in parts per million. Solventless has no purge stage because there is nothing to purge. The flavour is closer to the living plant, the high is full-spectrum, and there is zero risk of solvent contamination from a sloppy lab.
The trade-off
Solventless yields are lower (3–6% from flower vs 15–20% for BHO) and the cost per gram is higher. You're paying for purity, not volume.