Hi all. I wanted to open up a discussion on this residue that I have been seeing in wiped film distillation units recently. It seems to mostly show up on the glass leading up to the cold trap. We got a few theories running around the shop that range from lipids to vacuum grease. Has anyone seen this before/got an idea?
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Are you running cbd?
Yes, I’ve seen this very often. I believe it is a substance formed from terpenes dissolving lighter fractions of vacuum grease and leaving the heavier parts behind. I never conclusively proved it though.
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We have done a few CBD dominant runs but 95% of what we run is THC only.
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I do feel like I can see remnants of vacuum grease in it, both in its consistency and color.
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I get bits of it pretty regularly, zero chance that it is vacuum grease in my case.
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It looks exactly like what was forming in my latest batch of methanol winterized ethanol crude. Had these weird little sugar/fat things popping up everywhere
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Falling film crystalization?
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I was thinking maybe it could be CBD, the only time I’ve gotten this was when I ran some cbd with a little bit of residual methanol in there. Only one time I’ve had this happen to me
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I think it’s definitely a methanol thing. I’ve noticed it on my last two methanol winterized batches and never seen it before with ethanol winterizing. Not sure if it means the methanol does a better or worse job? It spits it out as it concentrates. I’m doing 5:1 meth to oleo, maybe need to bring it down to 4:1 or 3:1?
You can see along the walls in the below pic the same looking residue on there.
We don’t use methanol in any of our processes. Cryo extraction using denatured ethanol.
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Yes, I never used methanol either. That doesn’t have anything to do with it.
I’ve noticed a similar build up on the still and also on the rotovap flask in making the crude. I was assuming it was some sort of salt from the raw material. Ethanol would not wash off the residue but water took it right off. After that we extended our drying periods to avoid pulling those salts in our cryo-ethanol extraction and we have avoided that residue.
I’ve seen this while purifying terpenes err cleaning up a range of low boilers
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I have worked with wiped film for about 2 years now off and on and I can Tell you this is most likely NOT vac grease. I have had a few thoughts about what it could be and my main guess is just extra plant material, flavonoids, or just unknown compounds that come along for the ride when doing ethanol extractions. I should probably try and scrape some off of our wiped film and see if I can Identify it via GC-MS. Either way I figured out a way to clean it off. You can run 100% EtOH then switch to 50/50 EtOH and DI water then finish off with plenty of EtOH. I dont think it has anything to do with MeOH either but there are trace amounts of MeOH and Ethyl Acetate in bud which could just be co-solvents that drag out even more undesirables. Those undesirables could have similar boiling points to your target compounds causing them to evaporate and re condense in a “clean” location.
I would bet on lipids. Had a similar fraction the other day while distilling mother liquor. Had an almost sweet and citrus kind of smell. Collected maybe 0.5g by scraping it out of some lines.
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Man this makes me really want to go get a sample now.
Sample in question:
Hmm, this looks a little different than I expected. Are you going to test it? I bet it dissolves in water.
Collected it because having extra samples is never a bad thing. Didn’t come over at cananbinoid temps though, so not sure who I could even send it to for proper analysis.
You see how much I have. Was planning on “winterizing” at different ratios by:
Adding ethanol to about 1:1 → Freezing → See what happens → Add etoh to 5:1 → freeze → wait → 10:1 → etc