Ahh I see the relationship thickens. So I have kilos on kilos of cold trap terps. Literally an abnoxious amount. I just want to clean them up and remove the ethanol from the cold traps with little to no loss of terps.
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I don’t work much with ethanol but it sounds like the big issue with terps and ethanol is that they form azeotropes. @tweedledew had a great thread about how to solve the problem and is generally a pretty smart guy, maybe he can lend some insight. I know there was discussion about using different zeolites for a ghetto kind of adsorption chromatography to exclude the EtOH but that’s getting pretty involved.
The other option I guess would be pull mega deep vacuum on a very very tall packed column to fractionally distill them below the temps where they degrade
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I dont know if they actually do form azeotropes but thats a good thought to follow up and do some research on. Ill try and look for that thread your talking about and see if I can learn anything from it. Im not going to do columns at work unless its a last ditch effort. Mega vac seems harsh and like I might lose a lot of the sesqui terps. But no ideas are bad ideas at this point! Thanks for your insight.
The same thing happens to me, what you realize was after the extraction with PHO, I put a decarboxylated the wax, then I mixed it with ethanol and then I put it to winterize up to - 50c, later it was filtered with a pump to stop the lipids and waxes, then it was put in the rovoor to distill the ethanol and leave the oil fll spectrum, after putting the oil at high temperatures it began to crystallize
Here’s the thread I mentioned: A (likely) unsolvable problem with ethanol extraction (keep them terps!)
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Hey man I think I know what you’re trying to say and if it were me I would winterize, roto down your extract to get off ethanol. Then decarb. 105C for about an hour or till the lil bubbles stop coming. The picture you’re showing looks like THCa crashing out. If not then its lipids and waxes precipitating.
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This is probably the best/most effective method I’ve seen
Seems like real low and real slow + agitation might be able to get the job done for terp retention
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Either separate your terps/crash your crystals, then decarb separate. Or do a low temperature high pressure decarb (with a catalyst if you want, it’s around the site somewhere).
as @SidViscous has already pointed out this seems very much A (likely) unsolvable problem with ethanol extraction (keep them terps!)
louching into a hydrocarbon (pentane) helped, but didn’t really solve the problem as far as I could tell. @tweedledew wasn’t working with the greatest of terpene profiles to begin with, and I don’t recall sampling the results +/- louching, so your milage may vary.
do you have analytics on that fraction?
what percent is actually terpenes?
how much THC/THCA is in there?
I assume you’re already doing as @tweedledew suggests, and separating your fraction before decarb…but you’ve got 30-40% THCA in with your terps.
even if they don’t, part of the problem is that many mono-terpenes have boiling points lower than or very similar to ethanol. So simple evaporation/distillation isn’t going to get the job done.
best I’ve got would be louche into (say) pentane then try various magic dirts/solvent systems to achieve separation between your terps and your cannabinoids. the ethanol will be gone and you might have a terp fraction than no longer requires decarb. rumor has it this separation can done using lighter hydrocarbons. see Color remediation chromatography for details.
I don’t claim to be a chemist, so blame @MagisterChemist if it doesn’t work 
this is not quite the same strategy @SidViscous is suggesting, but seems at least as convoluted.
@NoHeatNoVacuum seems to have the simplest and most effective solution: No Heat No Vaccum
@SaigoMachuPicchu: that is THCA crystalizing.
Your decarb step is insufficient.
I recommend Decarb under pressure to retain terps? which is also explored under So I made a thing to decarb with....
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What was your primary extraction solvent?
PHO often means “propane honey oil”, but that is the product of the extraction, not the extraction solvent.
How did you decarb?
Why did you decarb before winterization? (Why heat your extract twice?!?)
Do you know how big of a column would be necessary? There a few local terpene distillers in my area and I know they have 2 and 3 story fractional columns. I always assumed their size is more for scale/speed than selectivity though.
Seeing as how the regulations in Florida are now super tight I do not think louching is going to be a very good idea. I have done anaytics on the terp fraction. So when we make our sauce the extract is crystallized as far as possible and then the crystals are separated through a sieve and set aside. The terp fraction was tested at 40.7% THCa and 37.6% THC. So that’s 73.3% total THC after decarb. Our extraction techniques are pretty clean so if we assume 12% terps, 4% EtHO, 4% other flavonoids and 6.7% minor cannabinoids does that sound right? Unfortunately my GC isnt calibrated for quantification of terps I only really do identification through the NIST database. The fact that they have similar boiling points is the reason I have been trying to do the reflux route. I just need to find a temp of my coil that allows terps to stick around, mostly, and EtOH to fly out of the top of the condenser.
At this point I feel like there are a few plans of attack.
- Louching, which I’m not psyched abut becuse there is probably a even lower limit for the hydrocarbons I would have to use there.
2.Thin film spread out in a vac oven which then gets purged like shatter. My personal favorite.
- Rig up a heated vibrating tray with N2 gas blowing over the tray. I could do this in my fume hood and turn on the vent to promote more air flow in the environment. The most labor intensive but also might be the most fun setting up.
That seems like a LOT of THC for a terp fraction. How hot are you getting your material along the way?
Dropping it 5C might help you drop more THCA rather than decarb it.
I dont have analytics on/have not seen analytics on sauce fractions I’ve participated in, but was under the impression that 35-45% cannabinoids was the target. I may be wrong on that.
Pentane is easier to remove than ethanol, which is why It is being suggested. You might still be correct, don’t know what your rules look like or what they are changing to.
OR for some reason (pressure from the CO2/must winterize crew I presume) decided ethanol was ok at any concentration!
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Yeah it is a LOT, when I first saw that’s what the concentration was at I was blown away especially because the crystallization on this strain was a crazy amount but not fully crystallized like I have seen. I think we could have probably tried to recrystallize again but the 1:1 ratio of THC and THCa was probably inhibiting the crystallization. Or the amount of EtOH was probably to high causing the saturation point to not be ideal for crystal formation to go to completion. We do an initial heating at around 75C to agitate the extract and promote growth. Throw the covered pyrex into a “Heat Cave” at around 80C and let it sit to crystallize. If the saturation point doesn’t seem like its good it will take a trip into the vac oven to try and get residual solvents down and then back in the heat cave. 35-45% cannabinoids seems like a great target range for the terp fraction. I was thinking of doing a 10:1 extract to pentane to try and displace/remove ethanol, sound right? I haven’t finished up my supplemental readings given by everyone in this thread so I will have to complete that before I go about trying crazy things with this extract.
75-85F might be more appropriate based on what folks are doing with hydrocarbons. Would certainly reduce the level of decarb you’re seeing.
Edit: and up thread
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Depends on how quickly/cleanly you want to distill. More height/plates means better separation, more cross section means you distill faster. The biggest thing in my mind is running cold enough to not oxidize the compounds which means deep vac and a very cold condenser. Sparging with inert gas helps prevent oxidation but makes it much harder to cut clean fractions and would make the solvent codistills more readily.
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Yeah I didn’t do the crystallization on this specific batch that I am working with so what was really done is up for debate. The person who was spear heading sauce at the facility is no longer employed here so I can’t really ask them either. I’m hoping to be a little more involved so that i can help reduce the level of decarbing and increase the level of crystal production! I work with @THChemist so I’m aware of how he has done sauce in the past. That crystallization at room temp was with a strain that crystallizes no matter what. Wish I only had material like that to work with because life would be a lot easier! Thank you for all your insight and help. I’m going to post a picture in a minute showing off our Inert gas sweeping/vibrating ethanol removal set up. @NoHeatNoVacuum get ready for this beauty.
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Got my nitrogen pumping, hot plate heating, and vibrator vibrating! Also got the hood pulling in some air. Hopefully something changes.
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vibrator and blow job?
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