Methanol for winterization


If a solvent like acetone is used for winterization, and it is polar and non polar, will it leave some fats and lipids dissolved? I would think so. This is why I want to use methanol. Even cryo temps with ethanol I cant get all the fats and lipids out (I always get azulene second pass which is from fats and lipids)


The idea to use a less polar solvent would be to further remove the non polar lipids (after removing most lipids with methanol).

But anyway, dealing with hexane, I don’t like it, at part because it is toxic, and at part because I see co-solubility issues with cannabinoids at quite low solid-liquid ratio. (while their solubility is at its highest in methanol)


Are you referring to my remark about analysis ?

I could use ethanol or methanol for crudes and refined extracts (not for oil based tinctures), but sample dissolution takes more time at room temperature (I usually don’tn heat the sample), and I preffer to inject the least amount of lipids into the GC (lipids which separate faster in acetone at room temp).


Hexane is comsidered generally safe for use in manufacturing ptocesses in which humans get exposed. In fact despite the gasoline smell the sheets about methanol safetey refer to exposure consequences as mild generally. This assumes folks practice common sense proptocols really common to Most slovents.

Here is a policy making page used by goverments and elected officials made available by the World Health Organization. The reports of damage from toxic exposure are vague enough so as not to bias the overall report. There seems to be at least anectdotal evidenve that long term exposore may cau nervouse system damage but the report also says this is vagues enough so as not to be confirmed.

Simply do not ingest it and you will be fine.


I did a methanol 1-1 with a first pass and dam did she look beautiful after. Just make sure you have enough ventilation and you will be good.


Indeed if one follows some guideline, it is okay.

I would just not say that it is as safe as ethanol and acetone (which are still inflammable and toxic :skull_and_crossbones: !), especially if occupational use is envisioned.


Do you think solving in 10:1 is necessary? If using pure methanol do you think you could get away with something like 5:1 or even 2:1?


I think it does not matter really just so long as there is enough to cover it real well. I just estimate a few hundred milliliters into one ounce of crude and it seems fine. If there is a n optimal ratio then I am not sure what it is. I almost always want at least a 2:1 ratio when disolving things but that is just personal preferences.


Are any of you guys doing your initial extractions with methanol?


@Roguelab was talking about using pure methanol for extraction in the ethanol azetrope thread, maybe he can chime in about this :slight_smile:


Yep bring down methanol to -80 or -86c depends on Wich freezer
Extract biomass in Bucket tech and winterize in same methanol If volume is large ( i often still have Some fats and Waxes left in My first filtration after extraction ? ) done at low temps to make sure No biomass is in Before warming up
Then distill to crude and proceed


at room temp is methanol more prone to pulling undesirables than ethanol?


yes, even at low temps. Methanol is more polar which is why it works so well with Hexane washes.


so really its not better than etoh in the initial extraction process


I would say no, but depending on filtration and final product it could be viable. For instance if you are going into distillate it could be wroth investigating. IF you extract at super low temps then warm up to room temp fat/wax winterization, run through Alumina Oxide, scrub with carbon/T5, then brine wash w/Hexane, D-gum, Evap then SPD you will save a few evaporation/dilution steps (which depending on your volume and evap capacity could results in major time savings). Does that make sense?


indeed it does however at my scale (basement caregiver) i typically dont go through all of those steps…
room temp etoh extract
filter, carbon scrub, bentonite scrub
evap then spd


Awesome! Love it, Id definitely exclude Methanol as an extraction solvent. Whats your average extraction size?


typically ranges anywhere from 20 to 100 pounds of trim once every few months. im at the level where i dont go through enough material to justify more expensive equipment. but the equipment i use now i end up losing 20-30% of my ethanol during the evap/reclaim process


Totally understand. Are you trying do tighten up on your losses across the board and/or improve your extraction method? Do you have panda’s to help with solvent separation/recovery from your source material?

To improve your solvent recovery yields you can try doing batches of 800g and spinning a few times in your Panda. You will maximize the ethanol return and allow for a slower evaporation. Because you extract at the volumes you do this is an option. You will be able to use a little more ethanol per extraction to improve extraction efficiency and reduce the total load on your panda’s which will increase its ability to maximize separation, and slow down your evap using lower temps will help you recover more ethanol.

Anyway just my 2 cents :wink:


ya i typically get back about 95% on the initial extraction, its the evap in my cobbled together buchi rotovap where i must be losing. I use a dewar style cold trap condenser on the roto so i think im losing etoh here.