Winterization
Also known as: Dewaxing
Winterization is a purification step that removes plant fats, waxes, and lipids from a crude hemp extract by dissolving it in ethanol and chilling it until the waxes drop out.
Crude extract straight out of a CO2 or ethanol extractor carries more than cannabinoids and terpenes. It also pulls plant waxes and fats, which dilute potency, make the oil cloudy, and shorten shelf life. The fix is simple chemistry: dissolve the crude in food-grade ethanol, hold it around -20°C (-4°F) for up to a couple of days, and the waxes solidify while the cannabinoids stay in solution. Cold filtration catches the solids, and the ethanol is evaporated off and recovered.
Winterization is standard practice between extraction and the next refining step, whether that's distillation, THC remediation for broad-spectrum oil, or crystallization into isolate. The trade-off is the usual one in hemp processing: every added step makes the oil cleaner and more consistent, and every added step risks losing some of the lighter terpenes along the way.
The consumer check is the same as for extraction. Because winterization uses ethanol, a batch COA should show a residual solvents panel with ethanol well within limits. A brand that can't show you that panel for your batch hasn't earned the benefit of the doubt.
Related terms
- CO2 ExtractionCO2 extraction uses pressurized carbon dioxide, held in a supercritical state between liquid and gas, to pull cannabinoids and terpenes out of hemp without a chemical solvent.
- CBD IsolateCBD isolate is pure cannabidiol with all other cannabinoids and terpenes removed — typically 99%+ pure CBD.
- Broad Spectrum CBDBroad spectrum CBD contains the full cannabinoid and terpene profile of the hemp plant with the THC removed.
- COA (Certificate of Analysis)A COA is a document from an accredited third-party lab certifying what is — and isn't — in a CBD product.
- TerpeneTerpenes are aromatic compounds found in cannabis (and many other plants) that give each strain its distinctive smell and flavor — and may contribute to its effects.