BHO clean up tech

I know ideally I’d be running cold solvent and inline dewaxing…

However, I would like to discuss what to do with an impure extract without sending it off to be refined for distillate.

  1. Winterize aka cryo freeze butane solution for 2-12 hours (thc will crash out as an oil)
    2.pour off the terpene fraction into a prechilled 2 liter pyrex measuring cup
  2. pour that same solution gradually into a clean jar. The measuring cup will catch any solids that came across the initial pour.

Now we have two solutions:
Butane- terpene

I would then like to wash my dirty thc without any chance of decarboxylation… Which solvents do you think would offer the best separation of fats from thc while avoiding decarboxylation during the purge of solvent?


PS… I used to collect this same fat/thc fraction when I thought it was just fat. I would use hot water to clean the chunky sand off the bottom of my Mason jars and Buchner. Then I would pour into a plastic solo cup that I poked 2-3 holes in the bottom.the hot water washed the greenish brown fats/thc into a white powder.


you are not using the term “winterizing” in manner I have seen it used before.

winterization is generally used to describe second solvent dewaxing. Usually with ethanol as that solvent.

you could check out these two threads to get a better handle on the term.


It is unclear from your description what you’re trying to achieve. You certainly seem to be trying to achieve it in a non-standard manner. That in itself is not a bad thing, but it does make it harder to figure out how to help you.

the 2-12hrs in cryo would be a good start to single solvent dewaxing. except you don’t have a filtration step.

It would be a good start to diamond mining, except you haven’t dewaxed yet.

perhaps telling us your desired endpoint?

what is this “chunky sand” of which you speak? do you not have at least coffee filters in the end of your extraction tube?

do you have a vacuum oven or chamber? I assume you don’t have a rotovap.


I consider the process of single solvent dewaxing to still be winterizing and that’s why I said that sorry lol. My filtration step comes in two parts. First I crashed both the good and the bad (thc/other stuff) leaving a terpene fraction that can be reintroduced later. This is a great start for sauce tech or slabs.

I have a rotovap, vac ovens, short path, wiped film And a closed loop with all the fixins. I gots butane and ethanol but willing to try heptane or pentane soon.

I could make more refined extractions out of the system if I ran colder solvent and inline dewaxed with various filter plates/filter paper/filter media. However, I want to talk about refinement of an impure extraction.

I want to separate the fat from the thca without decarboxylation during the purge of my solvent so that I can reintroduce a more pure thca solution to the original terps solution, homogenize and pour off as slabs.
Side note Im also thinking the initial single solvent crash off can be a tech for separating terpenes from thc prior to distillate, reducing the waste of terpenes during Degas/decarboxylation. Terpenes can then be upcycled into something worthy.


:slight_smile: which would be why @Sidco_Cat is working on a nomenclature project…

whoops: sorry. I took the solo cup as in indication that you were still open blasting. it seems out of place with the rest of the equipment you list.

the primary issue folks have with winterization using ethanol is that purging the ethanol also looses a big chunk of the terpenes. if you’ve already poured them off, then winterizing your “thc + fats” fraction would seem like the correct response.

solvent recovery is mostly done in the rotovap. then into the vac oven for slabs.

making Ethanol based shatters is a thing, so there is no issues with decarbing during solvent removal. or more correctly, that issue can & has been addressed, and is easily managed with the weaponry you have on hand.


I once heard through the grapevine that “winterization” was a tek developed in Denver. You just put the slab out in the snow for a couple of days to remove the fats & waxes…



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Cool I figured ethanol would be ok considering the “absolute” that people make.

I guess I just haven’t found a clear cut decarboxylation chart referencing temp and pressure. I did see one somewhere but it was hard to interpret. Im also aware of the formula p/t =p/t but my head hurts thinking about applying some math rn lol.

The solo cup was an example of dat low budget tech just for fun lol. It actually made a pretty clean looking semi sticky white powder/crystalline. I had a lb of it in a sandwich bag I almost sold for 50 bucks then some guy dabbed it as a joke and said he had never been so high in his life. We then melted the product down into a black glass and people loved it BC of how glassy the shatter was. If it aint shatter fam… Lol

This was like 5 years ago^


This industry is so interesting. Unlike fashion or food that span the nation, this industry lives in state-tight compartments. On the east coast and in Michigan shatter matters! They are not all on the distillate train yet. Funny. I predict that when those last states in the south get from glower to shatter to distillate then flower and shatter will make a comeback in Colorado and Washington and we will start all over again.


sounds like you were wandering around with a lb of thca isolate…

a recrystalization out of pentane would have given you diamonds ahead of their time.


the traditional response would be ethanol (aka winterization). doing something non-traditional has often been the route to breakthroughs.



why are you using silica gel?

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If I cold boil during purging of ethol in my vacuum chamber with a cold trap to catch the ethol… Will I retain the terps then?

I never said I was. I linked to a description of winterization as understood by this community to enable more effective communication with @Apothecary36 for the sake of exploring their problem.

You are commenting on a link to @Future’s winterization tutorial. (which might be the best place to ask the question)

my understanding is that he is using silica as a 3 dimensional filter-aid. which makes things go faster, and reduces filter blowouts. both of which are desirable outcomes from a production standpoint.

That said, if you really want know the intention of the original poster… you’ll need to ask the OP (@Future), not me.

Unless of course that question already came up in the winterization thread I linked to…in which case you click on the link I provided.

In terms of recovering THC from waxes the selection is of course what disolves THC very well but waxes not at all?

Answer: There are a few but the best choice is methanol really. That is the most polar and it readily desolves THC. One lab test peer reviewed for crime labs testing tested four solvents for max extraction of THC and methanol won by a bit.

I tested six solvents on just plant waxes and none of the polar solvents disolved wax very well or at all. Methanol not at all. As the polarity climbs the waxes seem to disolve better but until the hydrocarbon and conjugated hydrocarbon was used the waxes did not disolve all that well.

Here is the wax test. I do not use ethanol in my lab as for me it is a poison but ethanol would land somewhere about acetone if it was pure. Pure methanol is delivered from Amazon to me in a couple days and cheap. Pure ethanol is hella spendy owing to tax.

I now have refined enough isolate to repeat the wax test shown but now on clear isolate but have not fiddled with it yet. Methanol will drop waxes out like mad just at room temp when you disolve shatter in it by stirring or heating and it does so pretty fast. It will denature your compound and make it easy to grab most other gunk too then by filtration. I would recover in methanol then filter over a prewetted alumina (220-240 grit) column. That would clean up any extract irregardless of starting crude and recovery is nearly 100%.

I have done this for a few years now and it is fast and it works.


some of them will stay with your material. the lighter (more volatile) ones will end up with the ethanol in your cold trap. if using an oilless pump, you’ve got yourself an ice cold terpenni.


Haha I love it!

If you freeze the solution with different volumes of solvent, you can achieve a pretty nice removal of fats first, then reduc the solvent volume and crash out much cleaner THCa

I disagree about winterization. The earliest literature I remember finding on it years ago was in regards to the heavier triglycerides dropping out of raw vegetable oils, even when no solvent was present, and sometimes at room temperature. It is not solvent specific, and it is done “dry” (no solvent) with food oils all of the time. It’s mostly a viscosity issue we deal with in our industry. Unless you are going for more precise “fractional crystallization,” like the example above (3-stage winterization/filtration is another good example of doing it “wet.” Again, not solvent specific. It does seem specific to the concept of crystallizing/precipitating fats and oils through temperature cycling and insolubility.

Maybe consider some extra cleanup steps (some of which have been discussed in other threads here) - such as silica filtration (even full on chromatography maybe) or salt water washing the solution (glass lined stainless steel vessels, anyone?).


You sure it’s not chucking it out in the snow for a couple of days? :wink:

I was specifically referring to how I’ve seen the term “winterization” used in the cannabis industry. Where I have almost exclusively seen a distinction made between single solvent “dewaxing” and secondary solvent “winterization”.

I don’t disagree that where possible we should harmonize our jargon with that of those that have gone before us.

I’m curious to see how the ASTM committee @Sidco_Cat mentions in the Glossary will resolve this and some of the other jargon we’ve developed.


I’ma get butthurt if we settle on winterization being an ethanol process.:joy: