Bucket Tek (Cold Ethanol Extraction on a Budget)



I never hear anyone talking about the fire risk of putting ethanol in a washing machine or spin dryer. It is not a problem? Brushed motors make lots of sparks, do these applieces not have brushed motors?


I have made my own ethanol. It is 92%. Do you think this is ok? I can dry it out to 95% with molecular sieves.


I guess that depends on how you made it. It may need deodorized with carbon, and distilling it through ceramic raschig rings will get it up to 95%. If it is pure ethanol and water, and you don’t want to distill it, you can dry it out with silica gel, magnesium or sodium sulfate, or other desiccants. If you use mol sieve, you can dry it past the azeotrope to 100%, which is why I recommend using other materials and methods.


Question. How much does 2L of flower weigh when you do this SOP?

I’m looking for a mass to volume ratio between the flower and ethanol.



How dry is you flower? How fine has it been ground? What % of it is Cannabinoids? What % terpenes?


Oh. I was just asking about when you do it.
I wasn’t asking about particle size or potency or anything else that would affect the extraction.

Just curious about when you measure out your 2L of flower, how much does that weigh for you?


The weight of flower is highly dependent of all of those variables… I don’t have an answer for you. That’s specifically why i used a volume measurement vs weight


I wish I had seen this before I did my etoh extraction yesterday. I’ll give it a go next run.

Some 200 proof
Centurion pro trimmer ran trim


Would it be wise not to agitate the extraction bucket while it soaks? How are you guys pouring off the etoh from the extraction bucket while keeping plant matter behind? Does the plant matter go into a bubble bag? Also are you guys just using food grade 5 gal buckets for this tek?


@square_root_pharms: I see at least 4 references to using bubble bags to contain the material. Yes, they help.

“Buckets” as large as 275gal have been mentioned. you could use 4oz mason jars. food grade HDPE buckets will work. as will 50gal stainless steel mashtuns.


Would agitation or tumbling of the extraction buckets during their soak be worthwhile?


it would allow for a shorter soak, but would be more labour intensive. your call.

try it and see. report back.


I’ve got a cement mixer I figured making a sleeve to accept a 5 gal bucket would be easy enough and might IP the yield slightly over no agitation. Who knows I think I should try the basic bucket tek first and go from there


Hey Everyone, I decided to give the Bucket Tek a go and thought I would share some of my results and methods.
I used a large stainless steel pot and 200 proof ethanol, they were pre-chilled to about -25C. Roughly 4 pounds of Dry Ice was added to the ethanol in the pot and I let that chill for about 10 minutes, my temperature probe only handles down to -50 so I cant be sure what temperature I ultimately achieved but I waited about 5 minutes after it hit the minimum. I opted to go with 1 pound of hand trim in a 73um bubble bag and 1 gallon of ethanol all in one batch, I left the dry ice in the ethanol while soaking/extracting. The trim was fully submerged while within the bag and lightly agitated every 2 minutes for a total soak time of 10 minutes. I poured most of the ethanol into my storage container and used thick rubber gloves to squeeze what I could out of the bag without freezing my hands. Leaving the trim inside the bubble bag I put it in the Panda Spin Drier for 5 minutes and ultimately ended up very little alcohol loss. The solution was a little greener than I had hoped so I threw down some Celite and Activate Charcoal powder and filtered 2x’s with vacuum assist to end up with a beautiful golden amber solution. Using a rotary evaporator I removed most of the ethanol with low heat and high vacuum; I then transferred over to the vacuum oven for a final purge keeping the oven between 95-100F at full vacuum. In the end, I had a beautiful slab of shatter that tested at 93.4% total cannabinoids.


@TreeMonsters looks fantastic! thanks for the 1k word substitute.

Unless that’s “total acidic cannabinoids” 93% seems a little high to me.

Assuming you achieved 100% acid form, you should not be able to exceed 88% “active”. Low 80’s for “total activated cannabinoids” is absolutely achievable.

Any chance you could share the COA? or at least the part showing the numbers and the lab who called it?


Hey @cyclopath , so according to the fine print I am not supposed to reproduce, except in full, without written consent, but it has names and addresses and such so I feel that I probably would be best to not post it at least until I speak with the lab directly. However, here is the break down of the results: 87.93% THCa, 3.03% THC, 2.04% CBDa, 0.38% CBG. The lab we use is Agricor located in Denver, CO; the total potential THC is 80.16% total potential CBD 1.79%.

Hope this help illuminate the details a little better, I just rattled off the total cannabinoids earlier because it is the primary figure they list.


those numbers sound totally legit. especially with that pic and a scrub. listing the total cannabinods in the manner they do is mildly deceptive imo, given the state of knowledge at the consumer level.


Yeah, for a long time here in CO that was what was listed on packaging and deemed acceptable. That has since changed and we now have to specifically list the total potential THC as that is after all the psychoactive “get you high” portion :slight_smile: I am however very pleased with the concept of hitting a purity of cannabinoids that high regardless of their forms.

I recall an argument at a past lab between a sales rep and myself about how we needed to have our crude co2 oil testing at at least 80% to compete with other companies. I tried to explain decarboxylation and molecular weights… all I got in return was “Customers just see the highest number and they buy it, that is what they want!” This is the same person who thought we could simply “dry out” our THC oil and it would be shatter “like they make with butane”…sooooo

Anyway, I sincerely appreciate the fact checking. I’ll keep you posted on Round 2 if anyone is interested. Also, if anyone who has experience in this would like to weigh in on how I can best preserve my terpenes when purging that would be greatly appreciated. I need to achieve less than 1000ppm of residual solvent (ethanol). Information like levels of vacuum or temperature or duration.


both numbers are valid measures of potency. It’s certainly easier to appreciate the purity with the summed cannabinoid number.

as far as the fact checking goes, had a lab returned 87.93% THC on a QWET, then calling bullshit would be the appropriate response…we were just discussing the problem of inflated numbers over here…Shady Lab Results


Preserving terps and fully purging etoh is a very fine line. The boiling point of ethanol is relatively high, and the terps + ethanol love to form azeotropes.

Your extract looks phenomenal!