How winterization strips wax from hemp oil

Crude hemp extract carries plant waxes and fats along with the cannabinoids. Dissolving it in ethanol and chilling the mix far below freezing makes those waxes crystallize into a cloudy solid while the cannabinoids stay dissolved, so a filter can catch the wax and pass a clear, golden solution.

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Dissolve the crudeThick crude oil from CO2 or ethanol extraction is blended with warm ethanol until it is a thin, uniform solution.
Chill and waitThe solution goes into a deep freezer or a jacketed chilled vessel. Over hours, waxes and fats crystallize and turn the liquid cloudy.
Not cold enoughNear 0 °C the ethanol can still hold most of the wax in solution, so very little drops out and the filter catches almost nothing.
Filter while coldThe cold slurry is pulled through filter paper or filter plates under vacuum. Wax builds up as a pale cake while clear golden liquid passes through.
On to solvent recoveryThe filtrate is mostly ethanol. Next, an evaporator boils off the ethanol under vacuum so it can be reused.

A simple solubility model

This model assumes the crude contains 6 percent wax and lipid by mass and that wax solubility in ethanol falls exponentially as it cools, roughly by a factor of three for every 18 °C. At equilibrium, any wax beyond what the ethanol can hold comes out as a solid, and the approach to that equilibrium follows a first order curve with an 8 hour time constant.

All of these constants are teaching values. Real waxes are mixtures that crystallize over a range of temperatures, and processors confirm results with lab testing rather than a formula.

Try it: at minus 40 °C, slide the ethanol from 3 up to 15 liters per kilogram. More ethanol keeps a little more wax dissolved, so removal drops slightly, but the thinner solution filters much more easily. Then cut the hold time to 2 hours and watch removal collapse.

Where winterization fits

Winterization is most important after supercritical CO2 extraction, which pulls more wax, and is lighter work after a cold ethanol wash. Removing wax improves clarity and keeps later distillation equipment from fouling.

Large volumes of cold, flammable ethanol call for rated freezers or chillers, ventilated rooms and ignition control, and licensed processors document each lot for state or USDA hemp program compliance.

Sources

Comprehensive comparison of industrial cannabinoid extraction techniques: Evaluation of the most relevant patents and studies at pilot scaleFrontiers in Natural Products (peer reviewed, open access)
CBD Hemp: ProcessingPurdue University, College of Agriculture Hemp Project
Industrial Hemp Research: Cannabis Analysis, Extraction and PurificationNorth Carolina A&T State University, Biological Engineering

How to cite this model

Avid Solutions International. (2026, November 11). How winterization strips wax from hemp oil [Interactive 3D model]. Avid Field Lab. https://avidsolutionsintl.com/explore/winterization-filtration

Last updated November 11, 2026

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