I’ve tried the search and spent countless hours reading here but have not seen any data or comments on what the highest ethanol extraction temp one can get away with and not have to winterize as a separate step. I know cryo extractions shouldn’t require a separate winterization, but that term “cryo” is used kind of loosely.
Anyone extract in ethanol at some temp between 0 and -80C? What is that temperature and do you do a separate winterization step? I recall seeing that a lot of people extract at -40C. Do you winterize as a separate step for that temp? Or is that cold enough to avoid a winterization step and not get cloudy distillate?
Sorry if this has already been addressed, if it has, I’m having a hard time trying to find it. Thanks
Imo I think the term sub-zero is more accurate then cryo when it comes to going down to - 20 to - 40 and imo I think cryo is only an accurate term if you’re going down to - 60 to - 80.
Yeah, cryo technically refers to -150C or something around there to absolute zero.
I’m wondering what the warmest temp one can extract at with ethanol (actually more specifically 5% heptane denatured ethanol), and avoid having to winterize as a separate step.
Cool, thanks! Do you know if that number holds true for heptane denatured ethanol too? I’m wondering if the addition of heptane (in which lipids are quite soluble) requires even lower temps to avoid lipid extraction.
The reason I asked, is that normally my extractions don’t warm up past -60C. Last one got as warm as -50C and resulted in cloudy distillate. See post here:
So I’m wondering if I extracted more lipids than normal at the slightly higher extraction temp of -50C (in heptane denatured ethanol). Or if the cloudiness is from not doing a good job of pulling off the heads before swapping flasks during the distillation.
FWIW, I use 190 proof heptane denatured for extraction, I think the answer to your query is more along the lines of “it’s complicated” without more details from you.
We don’t know - without you spelling it out for us - what kind of filtering strategy you’re using. Are you exposing cold ethanol to cold biomass, or cold ethanol to room-temp biomass? Are you filtering, and if so, is your filter housing kept cold, and to what micron size are you filtering? How much enthalpy does your cold cannabinoid laden ethanol have to overcome before it goes out the other side of your filter? Is your reaction vessel being agitated by a pump or other means while in exposure to the biomass you’re trying to extract?
All of these things make a difference and it’s very hard to say without a process diagram or explanation from you. Sure, you can start with -70C solvent but if it’s warmed up to -5C by the time it gets through the filter, it’s probably going to pick up a bunch of crap you’ll have to remediate out to get nice looking disty. If you don’t know exactly how warm it’s getting, then you should find that out by putting in some temp probes and getting a datalogger you can trust (I personally like Omega brand)
Thanks for the reply. I extract in 5gal buckets inside a -80C freezer. Biomass and ethanol are chilled before extraction. Over the course of the extraction the solution typically will get up to -65 or so. Last extraction warmed up to -50C and resulted in cloudy distillate. Prior to that, I’ve never had an issue with clarity.
Minimal agitation. Just shake the buckets up a bit before they go in the freezer and after, right before they are spun. The extract is filtered cold over a large stainless buchner funnel style apparatus.
Is this filtering done inside of the freezer? If not that certainly seems like it could be where you’re getting fats/lipids warm enough to pass through your filter paper. If you can’t fit it in your freezer you should probably be monitoring the temp of the post-filtration liquid to see where you need to cut it off in order to avoid bringing fats into your solvent recovery strategy.
It’s not done in the freezer, and it does warm up a bit while it’s filtering, but at that point it’s just sediment. The weed is removed by that point. I’ve never had a problem with this method before, after close to 100 extractions with the same or similar conditions.
I just about have fully assembled a 3 dimensional filtration set up using cartridge filters that, during my initial tests reduced the filtration speed by a lot and resulted in full removal of sediment over 1 micron in size at an even colder temp.
The last extraction warmed up 10 deg. C more than normal, to -50C and the resulting distillate is cloudy. So I’m wondering if that 10 degree increase made that much of a difference in terms of lipid extraction.
@tetramethylsilane if nothing else changed that’s certainly where I’d start, scientific method and all that. I’d also be looking at why there was 10*C more warmup than normal, was it a hotter day, AC not performing as well as it used to or something else?
Normally I extract 10 pounds in 10 gallons of ethanol. 1 pound per extraction bag, 2 bags per 5 gal bucket. The temp warm up comes from removing the buckets to spin bags out in panda. To minimize ethanol volume I soak multiple pounds in the same volume of ethanol, so the buckets are in and out of the freezer.
Past extraction I did 25 pounds in the same volume so over 2x as many bags resulting in 2x as many trips into and out of the freezer which caused the freezer to warm up a bit more than normal.
At -50C would you expect significant lipid extraction? Enough to result in noticeably cloudy distillate? Seeing a lot of varying answers to this question in my search. Seems a lot of people extract at -40 without the need to winterize, others winterizing at -20C and not getting cloudy distillate.
I extract at -40C and when I do a winterization step I still get lipids on my filtration paper. It is minor amounts, however, results in distillate that is free of any cloudiness. I have read that -67C seems to be a selling point for some people as a magic number. I haven’t tried that temperature specifically but its worth the shot.
Correction: I believe the -67C number was referring to the absence of chlorophyll.