Bucket Tek (Cold Ethanol Extraction on a Budget)



so I’m not high on glue?

one can use saline washes to clean up a cooking oil based extraction…


I’ve never done brine washes on cooking oil, but I don’t see why not. Several washes with pH 7 water does a good job of deodorizing the cannabutter. You could probably even A/B extract THCA out of cannabutter, provided you managed to not decarb it all. Would probably be difficult to perform a thorough extraction with butter without getting to decarb temps, it could probably be pulled off with canola or similar. Then you’d just need a small amount of solvent for recrystallization!


Does anyone extract with anhydrous alcohol? It seems easy to remove the water from the azeotrope with a molecular seive, if that pulled over less chlorophyll it would be worth setting up I would think.


You would need to work in an air free manner, etoh will pull moisture from the atmosphere and become well…hydrated. Absolutely you can dry etoh, keeping it that way is hard. Most dry chemistry is performed on a shlenk line, solvents are all freshly distilled and dehydrated.Glassware is dehydrated under vacuum with a heatgun, reagents are kept in a glove box under dry inert gas, chemicals are added through septa or valves. Considering most extract at quite a low temperature with etoh to avoid lipid pickup, I would say most water soluble compounds are locked up.


Lots of companies are willing sell you 200proof ethanol to perform your extractions. Some will swear it’s better. I picked up some because it was cheaper than the organic 190 I usually use. I made sure it was manufactured in an appropriate manner (last of the water pulled with sieves rather than eg benzene).

I did not split a pile of biomass and run side-by-side extractions.

I did get great results, but I put in high end flowers, and ran at -80C, so I was expecting great results. after recovery, it was at 190 proof (no surprise). Second extraction seemed on par with first, but I made no attempt to actually quantify things like extraction efficiency, color, terpene profile etc.

While both extractions were the same strain, they were different runs, and differences in input would likely have confounded attempts to quantify 200 vs 190…all I can really conclude is that it was not obviously inferior to using 190 proof.

@Photon_noir has stated a couple of times that the azeotrope is almost perfect for our particular extraction (if performed at the correct temp).

My take is that if you don’t have your material & solvent cold enough to lock up the majority of your water solubles, 200 proof will pick them up, along with some water, and be at 190 (or less) moments after it hits your material. It loves water!!

New upcoming spd here

You are absolutely correct! It loves water, and getting it cold makes water condense into it, driving it to the azeotrope that much faster. My point is that if 200 proof is more expensive (over 5% more expensive), it isn’t worth it, mainly because it goes to azeotrope in no time… and if by some very careful procedures, you did keep it 200 proof, you would pull stuff you do not want (see plot posted by @gratefulhearted (sp?)). Also, just in case, you did right to make sure it was made properly, though they rarely use Benzene anymore because it is toxic to workers.




Can you elaborate on how the thca would crash out? Wouldn’t he just be making hash by washing trim/flower with high ph water? Would the thca crash out of the trichome heads when phd down?


I have a question for others running this method: do you pack the plant material on dry ice prior to extraction?

I’ve been running kief extractions in dry ice acetone recently, and there appeared to be a green tint to the run I did that was stored in the deep freezer then dumped in the cryo solution, compared to the run I stored the material packed in dry ice.

I ask because this tek is expensive to run when you have to pack all the plant material in dry ice for several hours, cause it takes a lot of dry ice! I was considering switching to liquid N for the freezing of the plant material, then throwing the frozen material in the cryo solution. Liquid N works in seconds so it shouldn’t be such a hassle. Thoughts?


Not running the tech yet, but it sounds like you just cool the solvent with dry ice, the biomass could probably just come out of a freezer and go into a bucket.

Does anyone put their biomas in some sort bag? I was looking into bubble bags or something. I’m looking for giant chemical and temperature resistant tea bags…


It may be easier to go with a bunch of smaller ones for handling/ easier draining. Plus if one rips it’s not a huge deal.


I was going to use this fabric to stitch my own since I couldn’t find exactly what I wanted:


Any suggestions or links for bags? (I see one was posted before I got to post this :joy:)

I’m going to try it out today with two stock pots and a colander.


Actually sorry that is a polyester, I don’t think that’s ok with ethanol… Trying to find a cheap nylon 25 mesh roll…


mesh for hash (mash710.com)


implies custom made 250lbs (dry!) teabags. from boldtbags.com

edit: boldt bags website seems to have issues at the moment.
google suggests contact@boldtbags.com or 877-450-2247.


Custom is good, thanks.

Future, can you please clarify some parameters of this SOP:
Acceptable temperature and moisture content range of the plant matter as it hits the solvents? Of course the widest possible rangewithout causing serious yield or quality issues would be ideal.


I’ve ran old bone dry brown, fresh, and fresh frozen.

All had good results, however the fresh frozen yielded my very first batch of water clear distillate


Great, thanks!!!

Sounds like moisture content and temperature of the plant material doesn’t matter too much when it is put into the solution, as long as the solution remains >-50C!


I tried bucket tech today.

I’m impressed with the amount of biomass I was able to run through.

What is the budget solvent recovery tech?