Step 4 - Winterize

Step 4 - Winterize

Introduction

Winterization is an idea popularized after Rick Simpson published his oil making procedure. Winterization is a step to remove plant waxes from the crude 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 cooking oil industry has always used winterization as one of the refinement steps. Interesting enough, winterization is typically done later on, further down the refinement pipeline. 

For cannabis products, winterization has normally been done between extraction and distillation. Historically, this has taken 24-48 hours to freeze the plant and large volume of alcohol, wash the plant then filter in the freezer to keep the waxes from melting. Again, all this takes quite a bit of time with the full volume of alcohol. Typical extractions use quarts, up to gallons of alcohol which must be kept near frozen through out the entire extraction and subsequent filtering.

Then in the summer of 2021, a thought came to mind through an observation that C02 extractions winterize the concentrated oils afterwards. Through a simple test, it was found the waxes are in fact very hardy, surviving a hot distillation. This is when Rapid Winterization was discovered..

In the past, winterization has been performed on large volumes of alcohol. What happens when its only a quarter cup of Ethanol? Time scales in a favorable direction. This small amount of alcohol needs very little time to reach -20c/-0f, 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 by creating an alcohol/dry ice bath and set the bowl in that (Be careful! Always wear protective gear when using dry ice). The dry ice bath can easy exceed -40c/-40f. Boiling action of the bath needs to be mitigated so not to disturb the extracted wash.

There is another benefit of moving Winterization to follow 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, waxes and oils as a dark resin. Warmed 95% Ethanol will be needed to melt this tough resin. Lower proof Ethanol has higher water content thus makes it harder to dissolve the resin. Again, here is the power of polarity playing it's role. Water is the most polar solvent on the planet, truly the polar opposite of the non-polar resin. In this mixture, you will 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 as the solution cools. Freezing this amount of fluid takes very little time. Waxes crystallize faster in this small volume of alcohol. 

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

Procedure

RAPID WINTERIZATION

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

2. Place this

3. Setup a paper napkin in a funnel, in a small jar, in the freezer. Drip a few drops of 95% ethanol in the napkin.

4. Place extra 30ml/1oz of 95% ethanol in a separate container into the freezer.

5. After an hour, pour the contents of the bowl through the paper napkin filter.

6. Once all the fluid drains through, pour the 30ml/1oz of alcohol over the collected waxes and let it drain.

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 above from a Rapid Winterization. The left picture is darker showing chlorophyll that bonded over time. This bonding goes for cannabinoids as well, so keep the winterization down to an hour.

Tip:If you have any Dry Ice left over, you can accelerate this freezing process. Be careful! Always wear protective gear when using dry ice. 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.  Place the bowl in the freezer to slow the warming.

Tip: Freeze 30ml/1oz of 95% ethanol along with the bowl of waxy solution. After passing the solution through the napkin filter to collect the waxes, pour this ethanol over the waxes to make a pass at collecting free cannabinoids.  you can then let the napkin stay in the freezer and dry out.  Save the waxes for topicals, etc.

Troubleshooting

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Science

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.