Step 4 - Winterize

Step 4 - Winterize


Winterization is an idea popularized after Rick Simpson published his oil making procedure. Winterization has long been a step in the industrial process of manufacturing cooking oil. The theory being plant waxes crystallize at cold temperatures into a visible mass that can then be removed through gravity, vacuum or centrifugal force filtering.

The freezing and crystallization happens over time in a cold motionless environment. Home freezers run at -20c/0f, sufficient for this to occur. Historically, Winterization has taken 12-24 hours to cool and precipitate the waxes. But that is with a full volume of alcohol, from quarts to gallons. What happens when its only a quarter cup of Ethanol? Time scales in the opposite direction. This small amount of alcohol needs very little time to reach -20c/-4f, the coldest temp in your freezer. If you have some Dry Ice left over from step one, you can speed up the freeze even more.

There is another benefit to moving Winterization after Distillation. By first Silting, then distilling in salt water, virtually all the polar and semi-polar compounds have been removed from the oil, leaving a majority of non-polar lipids, IE, fats oils and waxes in the form of resins. 95% Ethanol and heat will be needed to melt this resin. Lower proof Ethanol has higher water content thus makes it harder to dissolve the resin. Again, polarity is playing a role in this. Water is the most polar solvent on the planet, truly the polar opposite of the non-polar resin. 95% Ethanol struggles to dissolve this resin at room temperature. Add some heat and the resins give way to the dissolving powers of alcohol, but not the water. In this mixture, you can see the resins actually pooling and flowing like wine veins on the sides of a wine goblet. This is polar forces at work causing separation between the dissolved oils and water. Freezing this viscous fluid takes very little time. Waxes crystallize faster in this small volume of alcohol.

Once the waxes have solidified and are a visible mass, pour this bowl into a paper napkin filter. This allows the dissolved oils to flow through, but catches the waxes and other particulates. A true paper coffee filter is too thick and needs vacuum assist to draw out the fluid. All this should be performed at freezing temperature.

After the waxes have been collected in the paper napkin, save the napkin to harvest the waxes for other uses. Your bowl of dissolved oils is ready for final reduction.



  1. Place the bowl in the freezer for 1 hour.

  2. Pour the contents through a paper napkin filter.

Proceed to Final Oil


  1. Place the bowl in the freezer for 12 hours.

  2. Pour the contents through a paper napkin filter.

Proceed to Final Oil

If you have any Dry Ice left over, you can accelerate this freezing process. First, place your dissolved oils in a metal bowl. Place your Dry Ice in a larger metal bowl and add at least 91% Isopropyl. After a couple minutes, the boiling will slow as the alcohol reaches it's coldest temperature. Pour this frozen alcohol into a second metal bowl, so it stands still. The first bowl has boiling action that will disturb the settling. Now, float your bowl of dissolved oils in the second bowl. The dissolved oils will quickly reach a low of -40c/-40f. Let the bowl sit quietly in this frozen alcohol for a couple minutes.


For further reading on waxes, please visit Gray Wolf’s post on Plant Waxes.

For further reading on winterization, please visit Gray Wolf’s post on Winterization.

Tips and Tools

Tip: The longer the freeze time, the greater the yield losses. This is because fats, oils, and waxes are lipids which are non-polar. More time together means more bonding. Take a look at the color of the waxes from a Rapid Winterization and a Standard Winterization. The Standard will most likely be darker as more chlorophyll bonds over time. This goes for cannabinoids as well.

Shop Talk

Winterization is well known, well understood. This step is very important in removing fats and waxes. Its as simple as placing the wash in the freezer for some time, then passing the wash through a simple filter to remove the solid particulates. This has to be done at frozen temperatures since the waxes will melt at warmer temperatures.

This is a longest step because of the freezer time. Don’t be impatient and blow this off. Wax removal makes a noticeable difference in the final oil. Silting and Winterization use different chemistry for removing compounds so both are necessary for the cleanest oil.

If you do a Dry Ice chilled Winterization, lower temperature of -40c/-40f will crystallize more waxes.


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WARNING: Never distill alcohol near open flame. Alcohol vapors are highly flammable so always distill in well ventilated spaces.

This oil is appropriate for oral ingesting and vaping. Due to the potential of residual salts, do not torch this oil. Torch temperatures can reach over 760c/1400f and can vaporize any residual salts.

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