I’ve run into the same issue… We switched from cold ethanol extraction (from which the extract could be run directly on the pope) to CO2 extraction and now we’re having difficulties achieving over 80% THC in our distillate. With our EtOH extract we would easily get >90% THC after the 2nd pass. We’ve tried repeating the 2nd pass with our distillate from CO2 extract, but it won’t purify any more than ~80% THC.
We are going to play with our pope parameters and hope to be able to fine tune so that we get higher THC. But I think that you’re right - there is something else that has similar vp to the cannabinoids and is co-distilling.
wouldn’t winterizing drop said hypothetical “contaminant”?
if ethanol doesn’t bring it along during extraction, why would it pick it up from a 5-10 to 1 dilution of CO2 crude?
if it truly is a single moiety, shouldn’t it be discernible to folks running LC-MS/MS? (@SoStupendous, did you ever ask your 3rd party lab if they saw anything unique?)
I spoke at length with the chemists at the analytical facility we use in Colorado, after several attempts at discerning what our “mystery percentages” were, to no success. Their best guess was a terpenoid or isomer that they were unable to pinpoint.
That’s a good point. It could be something that quick fast and relatively cold ethanol doesn’t pick up from the plant, but stays dissolved in ethanol once it’s in. The high pressures of CO2, and the fact that the material is often milled to a finer particle size, might mean that supercritical CO2 pulls things from cellular areas that an ethanol soak doesn’t pick up. This is all just hypothetical though, and I could be wrong!
Here’s a surprising finding too: in two controlled experiments I performed, winterization did NOT increase potency of the crude! I never tested the “waxes” that we are throwing away, but the only way for this math to work, means those waxes are about the same potency as the crude. Its possible that the waste waxes are loaded with cannabinoids. If someone has test data on the waxes to the contrary, please share. Also, if anyone has empirical data that winterization increases potency, please share that! As of now, I have no reason to believe that winterization really improves the potency of crude. Who knows, it might not even be necessary to winterize before distillation, I never tried it myself!
If you don’t winterize you will for sure have more burnt mess in your boiling flask. I do agree that the fats can carry a bit of cannabinoids with them, though I have yet try and test the fats.
Quick question, are you referring to ethanol extracted crude or co2 crude when talking about winterizing? Ethanol crude i would agree, especially if its done relatively cold and fast, I dont see much potency change, but there is quite a big potency change for co2 crude, based on how much is removed.
I’m talking about CO2 crude and winterization. The two times I have tested raw crude from the extractor and then the same crude after winterization there was no increase in potency. I would have to dig through some old files to find the data. Have you done this experiment before and found something different? And yes, definitely a lot of solids were removed when winterizing the crude!
I have seen quite a big increase in potency from co2 crude → winterized co2 crude. I don’t have any of the data available, but I would see things go from mid 60’s to low to mid 70’s potency. I still do think the fats carry some cannabinoids with them still, but from what I have seen, the winterized crude is still more potent.
When it comes to distilling thats a whole different story, heavy terps, isomers, there is something that happens with co2 crude that needs more processing before distillation, many different opinions on what exactly is happening.
For me, I’ll stick to ethanol for making crude for now.
Hmmm, that might make sense if the crude is particularly waxy or lower potency such as 60% range like you said. I did just find my old test data on the batch I was thinking of, it was 79% total cannabinoids before winterization, fresh out of the extractor, and it was 79% total cannabinoids post winterization (2x overnight in 190 proof ethanol, -20C, ~1:4 dilution, lots of waxes removed on the filter paper).
My latest attempt at pre-processing to increase CO2 distillate potency is this:
Dissolve crude 4:1 in methanol
Add 3% h20 and winterize at room temp and again at -60C
Recover methanol on rotovap leaving 1:1 methanol to crude
Load into sep funnel with equal parts heptane and wash with brine at 4ph, 9ph and 7ph
Add 10 percent each: activated carbon, t5 and activated alumina to heptane solution, warm to 40C and stir
Allow solution to cool and then filter through buchner funnel
Pour solution over cake that is formed in buchner funnel a second time
Perform a final brine wash at 7ph in sep funnel to neutralize
Recover heptane
Distill
This is pretty extreme when we could just go cryo ethanol or hydrocarbon and get a much quicker and likely better result, but it’s not my company and I’ve got what I got to work with. This is my last hail mary.
Our current process is to dissolve in ethanol, winterize twice, carbon scrub, heptane/brine wash and distill. My hope is that the adsorbents work better in a hydrocarbon solvent and that the LLE with methanol removes some undesirable components.
I haven’t, but I’ll give it a whirl next go round.
I will say that I’ve never really had very cloudy water or any discernable emulsion layer when brine washing with our old method, but when I washed the methanol material into the heptane today I had both and it took a good few washes to run clear. Could be because I havent scrubbed the oil yet though.
Should have this batch distilled next week. Fingers crossed. I’ve also been messing around with extraction parameters with some help from people here. If I dont get the result I’m after with this process I will focus there.
@ExTek90 I was allways under the impresion that secondary metabolites terpenoohelos form in plantnglandular structures as trichomes.
It might be terpenes that your pulling not cannabinoids from the plant cells?
One thing that comes to mind is that when you u use a slovent as etoh it dissolves inside the whole plant matter so when you centrifuge it away some % of the saturated etoh stays inside leaving cannabinoids. Thats why analysts do a 3time labgrade iso wash to determine cannabinoid content in glp. It could be the same with other solvents be it co2 of ch.
@SoStupendous Im testing waxes that fall out of winterization with EtOh this week. Ill share the result if you will find any use in them.
From our experience a winterization of EtOh did raise the cbx content for 2-3%. But a later carbon/bento scrub decresed the whole content up to 5% in cbx and even 15%-20% depending on the ac/ben ratios in weight.
Were trying to figure out where an spd sweetspot lies in terms od preproces. Im almost sure that having wax in an spd will produce a tar like termsl degradstion product that dissolves only in benzene… And thats not cool…
Please elaborate some more guys on the wax issues if you can. I allways noticed a grand smell on the etoh waxes. Anyone else? Tnx!
I use a 1-10 ratio of crude oil to ethanol is my solvent and I use the diatomaceous making the 1 1/2 inch cake then mixing activated charcoal with solvent before I run through. but was interested in the silica route but don’t know which one is better.
Silica won’t do much with ethanol as a solvent because it’ll make pretty much everything elute if you use enough solvent and if you don’t, your goodies will stick to it. Also, 1-1/2" of DE is mega overkill. I use somewhere between 1/4-1/2" usually
DE is a filter aid; it just filters the other media out. It won’t do anything other than filter other particles out so if you expect it to clean up your oil on its own you’ll probably be disappointed