Winterization

Crude cannabis extract is dissolved in ethanol and then placed in a freezer or deep-freeze unit at temperatures typically between negative 20 and negative 40 degrees Fahrenheit for 24 to 48 hours. At these cold temperatures, waxes, lipids, and fats solidify and precipitate out of the solution while cannabinoids and terpenes remain dissolved. The mixture is then filtered through laboratory filter paper or a Buchner funnel to remove the solidified impurities. The ethanol is subsequently evaporated, leaving a cleaner, dewaxed oil.

Unwinterized cannabis oil contains plant waxes and lipids that can create a harsh taste, cloudy appearance, and may irritate the lungs when vaporized. Winterization removes these undesirable compounds, producing a smoother, more refined product. This step is standard practice for vape cartridge production, where clean oil is essential for both taste and device functionality. While winterization improves purity, it also removes some terpenes and minor compounds, which is why some producers prefer to skip it when making full-spectrum products that prioritize the entourage effect.