Post Processing "warm" EHO Solution

Hello F24K Friends,

Were in the process of bringing an Ethanol Extractor online, and I have some Questions and Concerns…
I was told the coldest our ethanol would be is -20 C on the first pass, and subsequent passes would be as “warm” as 0 C max. The unit requires a minimum of 30 Lbs of biomass and 30 gallons of solvent to run. Yes, there we have an industrial chiller. No, I don’t know why this Fiat sized machine can’t do better.

The idea is to be sure we pull all the desirable compounds along with the crap, to ensure a near 100% extraction of cannibinoids. In theory, this is great, but subjects my coworkers and I to some extensive winterization, filtration, and color remediation.

So, here are my questions/ concerns…

  1. Where to put the carbon scrubber? I’ve read on the forums here some people do it pre winterization and some do it post. Is there a clear advantage to one or the other? More specifically, does it have to do with the initial quality of crude solution? IE, is easier to implement this strategy when starting with a more pure solution? and will I slow or clog the flow by attempting to scrub such a low grade crude oil prior to winterization?

  2. What is the best way to stage the filtration to mitigate needing to change them as often? I should have access to 2 or 3 high pressure SS filtration vessels and can stage them either inline (which is the current set up, Large pore size to small) or in parallel depending on what should be most efficient. Here are my questions… For EHO post processing winterization what is the lowest micron you would suggest? I notice the 10 mic catches the majority of the fats and waxes. Is 100 too high? I believe the options are 100, 50, 25, 10, etc. With 3 vessels I was thinking of staging them in descending pore size, but hoping to catch more before the 10. The staging will obviously be predicated on what is deemed to be the correct/ appropriate sized final filter.

I really appreciate any advice, opinions, and or feedback!

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Uh, that’s not why you run cold ethanol to extract with at all, the idea is to pull less of the crap and as much of the cannabinoids as possible. If you run cold, you won’t pull as much fats/waxes/sugars that you’ll have to remove in order to distill cleanly. Also I don’t think 100% extraction efficiency is realistically possible (or at least, does not happen cost effectively and scale well). Something to consider for the long term.

I don’t think 0C is near cold enough to produce quality crude but I’m curious why on subsequent passes you get so much warmup. I would think you could do better than if you’re reusing solvent by puming it into a holding tank that’s jacketed and kept cold in between passes, though without more details it’s hard for me to know exactly what your setup looks lie.


Hello! and thanks for the reply.

I totally know what you mean. But this was purchased prior to me gaining employment with this company, and while it isn’t necessarily my job to get it on line I have to deal with the green soup it will inevitably spew…

Let me ask the “mechanic” some more questions so i can better address your other points.

You can definitely create fantastic end product with a warm EtOH extraction.

It might look something like this: warm extract, decarb, winterize (0C then 40C), recover EtOH, LLE with Heptane and Water, carbon scrub(if necessary), recovery heptane, feed to distillation.

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Certainly it’s possible but it’s a lot of work, certainly more work than if you don’t don’t pick up those nasties in the first place, and IMO winterization doesn’t scale easily, and warm ethanol extraction is bound to require more attention paid to reproofing your solvent.

If you’ve got the ability to get down to -20C it would certainly reduce the amount of cleanup you’re going to have to do after the fact, though I certainly sympathize with @TheMadDabber 's situation where they’re having to run & maintain equipment that they had no say in the sourcing & purchase of, because I’ve certainly been in that situation myself


Another issue is, you have to determine the solubility of THC in ethanol at different temperatures. If you’re not pulling 20%+ of cannabinoids because you’re too cold, you could be losing too much potential revenue.


Hey friends. So all in all, things have come on line very smoothly after eliminating the mechanic position and literally rebuilding ever connection I’m not unhappy with the current state of affairs. I do have a few questions.

The current SOP is…
Chill etho to -20 and fill the machine.
REcirc for a while.
Lenticular filter with carbon.
Send to winterization
Send through staged filtration.

The problem remains that were getting some weird nastiness after decarb. It was much worse but I added a final inline filter that has greatly reduced the amount of weird left behind during decarb.

WE DO NOT WANT TO USE A SECONDARY SOLVENT. Ethanol IS NOT recognized as a solvent in our state, so we don’t want to use anything besides ethanol for the entire process.

Pictures to come in the following post. The weirdness DOES seem to disolve in water.

@TheGratefulPhil @Demontrich @cyclopath

I would appreciate any insight and or advice you may be able to offer. Nearly certain it is not fats/ waxes. I know degumming is a big thing do we need to be adding that to the SOP? My thought is that as moisture is pulled from atmosphere into the solution some compounds are soluble in the water and essentially become trapped in solution because of their high affinity for water. And no we can’t really go too much colder than the - 20 to 0 C.

Thanks in advance!

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“Nasties” as in smell or solids?

When do you notice the issue (post decarb crude)?

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Post decarb.

There was some funk in the roto but with the new inkine filter its been clean

Sugars possibly

Do they dissolve in h2o or ethanol?

They most certainly dissolve in H20


I thought I lucked out and made thc crystals in the rotovap. Was sugars. Kinda looks like that. I posted pics, and a few others ran into the same thing (sugars).


that would certainly be my first guess (which I would almost certainly confirm by tasting them if they showed up in my rotovap :wink: ). there are several posts on how to get rid of them. I’m too lazy to go find them right now. I think @Akoyeh may have posted on the subject. I’d be tempted to wash the crude against water before decarb. I believe others find some flavor of magic dirt (t5?) effective.


Yup. Looks an awful lot like sugars. The issue we generally had with precipitation of sugars was when incorporating crude with MCT for tinctures.

Once we incorporated the AC/T5 filter tek we did not seem to have issues with sugars. I’m not with that lab anymore, and I neve had the opportunity to run appropriate tests to determine the efficacy of magic dirt in removing sugars, specifically.

@cyclopath, we should explore the idea of harvesting the sugars, again.


I can navigate the search bar from here brother. I just wasn’t sure exactly what the substance was and what to search for. Appreciate the advice. Legally, we cannot consume (cannabis) on location, but had the exact same initial idea :rofl:


Consumtion… I say testing.
Legal in my book.


If the unknown crystal ended up a bit stuck to one of your fingers, you could always go to the bathroom to wash it off…

Not suggesting the consumption of cannabinoids while working, that I do not generally condone. The waste products that are entirely unlikely to contain cannabinoids, though… Let’s just say I have greatly benefited from @cyclopath’s encouraged in-house organoleptics.

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Seriously. You need to know your product. Organoleptics: In House QC?

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Man and its times like now I would kill for onsite testing abilities cause the state run labs are laughable. Legit sent me a 114% test result for my sugar wax last week. and this week a winterized oil had “56% CBD” starting material tested less than .5% CBD. Went back to look at the tests and there wasn’t even a spike in that range… Also we make custom terp blends and will have terp results come back with terpenes that were never added to the distillate. SERIOUSLY FRUSTRATING


114% deserves a recalibration and rerunning of the sample.

The others sound like sample handling errors.

Labs that spun up because: Cannabis!! might not have the sample handling sophistication that labs that added cannabis to their repertoire do. Do you take samples to them? Do the hand write labels?!?

See if you can get in to chat with the lab director, calmly discuss the obvious sample handling errors. Work with them to reduce the number of opportunities for errors to occur (it’s almost always a human interaction with the sample).

“State run?”
Which state?