How To Winterize Rosin — 5 Steps to Remove Fats and Waxes

Use 190-proof ethanol (Everclear or similar). Do not use anything below 150 proof — lower proof alcohol contains too much water and will affect the process. While the rosin is still warm from decarbing, pour it into a larger beaker and add the measured ethanol. Stir to combine fully.

Step 3 — Freeze the Mixture

Once combined, place the sealed mixture in a freezer for 24–48 hours. The cold temperature causes the fats, lipids, and waxes to crash out of solution and form solid particles. These are now easy to filter out.

Step 4 — Remove Lipids Fats and Waxes from Rosin by Filtering

The filtering step is what actually removes lipids fats and waxes from rosin. Work quickly while the mixture is still cold. Pour the frozen mixture through a fine filter (coffee filter, lab filter, or bubble bag) to catch the crashed-out waxes and fats. The clean liquid passes through; the waxy material is trapped in the filter.

You may run it through the filter twice for extra clarity. The filtered liquid will be noticeably clearer than the original rosin.

Step 5 — Evaporate the Ethanol

The final step is to evaporate the ethanol from your filtered liquid. Use a hot plate at very low heat (or leave at room temperature for longer) in a well-ventilated area — ethanol is flammable. Never use an open flame near ethanol. Allow the alcohol to fully evaporate until you are left with clean, clear rosin oil.

Your winterized rosin for carts is now ready to use. Expect to lose 40–60% of your original volume from this process — the material you removed was the wax and fat content you didn’t want anyway. The remaining oil is significantly more potent per gram.