Methanol for winterization

I wanted to ask and see if anyone is using methanol for winterization. I heard that methanol will push more fats and lipids out then 190 will, but it is slightly toxic. I also had someone tell me that methanol is so polar you can crash thca out of it. Has anyone had any experiences with methanol and winterization? I’ve heard more good things then bad about it at this point I feel like.


Have you checked the MSDS for methanol?

Given the amount of ethanol I see on the floor in most of the labs I’ve visited, I would not substitute methanol without substantial improvements in containment.

Certainly wouldn’t recommend bucket tek


This is for winterization only. I already extract with hexane so containment shouldnt be a problem.


Methanol is the superior alcohol for winterization.


USA Lab Equipment makes a great closed filter system. You could pressurize the feed tank through the filtration body and into a collection tank.


How toxic is methanol vapor? I’m guessing sufficient air flow wont be enough? I can open extract with hexane in my lab without a problem because I have good air circulation, is methanol really so toxic I should filter enclosed? I am using vacuum to filter right now

Methanol works hands down better than less polar solvents and I typically run methanol cut down even more polar with an addition of water. I can “winterize” without any freezer or cold by simply adding some water to the methanol and then pulling it past alumina. Methanol has its own handling characteristics but methanol is routineky used by young folks using remote control engines on cars and planes and such. Incidental exposure does not seem particularly harmful although I treat all solvents except water about the same. I avoid exposure but really nothing out of the ordinary. Methanol is particularly useful IF you elect to run a liquid to liquid extraction of the volatiles on the compound as a follow on technique. In that case methanol is the only solvent that works very well because traces of it left in compound will not impact the process like traces of ethanol or iso will.

However if you are not running LLE that needs methanol I find iso cut with water has its own advantages and is sort of a toss up. :nerd_face:


The toxicity that you hear about methanol comes from drinking it, the same enzyme in your liver that converts ethanol to acetic acid turns methanol into formic acid inside your body.

When methanol is inhaled it does not reach your liver to be converted to formic acid so in that regard its safer to inhale than to drink methanol but as with most of the solvents we use you still dont want to be breathing it in significant amounts so isolating yourself from that vapor whether its with a closed loop system, a fume hood, or just the outside breeze is always a smart thing to do.


You can do room temp winterization with methanol add in some Alumina Oxide and you can really get good results!


I’d never do this at scale but i’m curious, if you use room temp methanol for primary extraction will you pick up waxes? If so, how cold do you need to be to not pick them up? Probably a lot warmer than the -40C for ethanol.

Probably not but you would pick up a bunch of chlorophyll.

When you winterize with methanol and water, how much water do you add? Do you do like a 190 proof but with methanol or do you do more than 5%? I’m planning on doing 12 hours in the freezer also (regular freezer not cryo). Just want the best results possible, i know I’m not getting all the fats with ethanol and freezer combo.


I find that 70% methanol OR isopropyl alcohol cut with water with do a great job at room temp winterizing. However it will pull slow through alumina. Some reports back to me indicate others like 80%/20% better because it filters easier. Methanol works better for me doing this but iso will also do it.


Thats very interesting! So you dilute in the same ratio as with EtOH (10:1) and the waxes start to precipitate out at room temperature?

Speaking of the winterization of extracts already extracted,

The waxes appear to precipitate out at room temp. However I am not so sure that precipitation is the right word. My tests indicate that methanol does not solvate those big chunks of white “wax” that form. This has always puzzled me these last few years. In my own tests the same amount of “wax” is removed whether the methanol is chilled or not. Chilling it does not seem to cause more to form. The logical conclusion is that the methanol just needs the integral (time) rather than one temp over another. This must mean that the “Waxes” are entrained in the compound and when the soluble parts parts disolve then the wax particules are released.

I concluded that the waxes I see are clusters of waxes liberated from the solubles that hold them rather the waxes themselves precipitating out of solution. My only real logical connection in this comes from a time lapse lab I did whereas the Methanol refuses to solvate the white wax but did saturate it so the clumps sank. This seems a pretty big clue in regards to how winterization is happening.


Ive done exactly what he’s talking about and tou can do a LLE extraction and never have to use a freezer. Also if tour running a hot condenser it works even better, methanol and water also pull tons of terps out that tou dont have to deal with in the spd


I can’t remember where I read this, but supposedly methanol treats fats like an liposomal emulsion rather than actually dissolving. So when the conditions are right the MetOH lets go of the lipids.

Sorry for the completely non-technical response but hope that leads to something.


Dealing with toxicity, methanol is very toxic by ingestion (as said above), but also by skin contact (this compound is the issue in adulterated alcohol). It is less harmful by inhalation especially if it very occasional. But still, it better require confining techniques anyway (closed system or fume hoods), and wearing some protective equipment (gloves, glass, lab coat). :woman_scientist:

I never tried to winterize with it, but I guess it would act well, even at room temp, especially dealing with neutral lipids.

The solubility of lipids is generally a matter of lipid polarity versus solvent polarity (versus temperature). I’m still not aware about cannabis fats, they seem composed of both polar and non polar ones.

Acetone can be a better option. For analyzing “unwinterized” extracts or oil tinctures, I use less polar solvents such as acetone (or sometimes hexane). At room temperature, a lot of white precipitates are seen. They disappear if the temperature is sensibly increased (above ~35°C), but re precipitates as soon as it cools down.


@Dr_Jebril Not sure why youd ever use hexane for winterization, its non polar and dissolved fats and lipids. Acetone is barely polar which means you can use it for winterization but its not the best, the reason I want to switch to methanol is 1 it’s completely polar unlike ethanol or acetone and 2 it has a stronger polar charge which will allow you to push out more fats and lipids at the same temp. Why even freeze your alcohol if you can winterize at room temp?


Hmmm thats weird. In ethanol I can dissolve my crude at 1:10 and even at 70c I can filter fats and lipids out. Sounds like acetone charge isnt that strong and let’s fats and lipids redisolve.

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