I’m just wondering if anyone has experience working with ethanol on small/medium scale? I’ve been working at it for 3-4 months and I can’t manage to get any extracts that aren’t quite dark in colour. I’ve done everything at very low temperatures for the extraction portion and am always left with a deep red extract.
I’ve tried varying freshness of bud, but I can’t ever seem to get anything other than darkness.
I tried a heptane redissolve with a bleaching clay at 80c for an hour but it’s still super dark.
I haven’t tried activated carbon yet but that’s next in line (I read it was more for chlorophyll).
I have heat up to 85c in the first solvent vaporization (just some classic distillation equipment, hoping to upgrade soon). Then after a dcvc separation and dewax I do a pull under vacuum.
Has anyone made a nice light/yellow/gold ethanol extract with ethanol as the primary (hopefully only) solvent?
I have succesfully gotten golden yellow colored extract with ethanol. I would consider myself very small scale, i have one 6"x24"jacketed column that i exctract with, i have about 10-15 gallons of ethanol total that i recycle.
I pre chill both the alcohol and green material in the freezer overnight, then transfer each “batch” (in my case 2lbs of nugs and 8L of ethanol split into 2L Boro glass containers) into a cooler full of dry ice. They both sit for atleast 20 minutes before being used.
I have an isopropyl/dry ice slurry in the jacketed part of the column and load silicia 60a and a tad of T5 filtration clay at the bottom of the column to aid in filtering. I put the material into a sock that i stitch together and then pour the ethanol into the column, the ethanol containers will be way too cold to hold even with triple gloves on, use a foam sheet that sometimes comes in shipping packages to hold the containers when pouring in. If you are able to handle the ethanol with just gloves, u didnt get it cold enough.
It doesnt really matter how long u soak for but i usually soak for 15 minutes and then it takes about 5 minutes to fully drain out for me.
From the 8L i usually get 6L back, so i put in 6L more ethanol that was prechilled in dry ice aswell. That is my rinse, that usually only sits for about 5 min before draining. I use this ethanol for the first soak of the next material. For trim i use it 4 times, for bud 2 times and for kief 1 time.
I throw my material into a centrifuge after its done and recover about 1.9L-2L (depending on how dry/wet your material was to start with), this extract is green when running kief and browinish/yellow when running bud or trim. I keep this seperate and is usually thrown in when i run heads and tails.
One thing i notice is that if the extract is left out in a bottle with oxygen in it, it will turn slightly red over time (a week of sitting there). So now i make sure to rotovape the extract right away and anything that is sitting with “air” around it is flushed with nitrogen. For example if i still have more ethanol to roto at the end of the day i blow nitrogen in before capping the extract resevoir. If theres anything in my roto at all when im done with the day i pull a full vac and then back fill with nitrogen. Since doing that my extracts have been staying golden yellow even sitting for awhile.
Wow, I really appreciate the detail! Thanks! That’s really helpful!
What % of alcohol are you using? is it azeotrope? Have you noticed a difference in freshness in bud? Do you think the silica is acting as dessicant with the alcohol? I was wondering if moisture is a big concern as well.
Are you just shaking cannabis and ethanol? Try ice and ethanol dry ice strips out more of the yellow then filter solution through a regular glass funnel to remove the flowers. Ten filter that through a vacuum buchner funnel (#3 fritter filter preferred) you should get more yellows then greens.
This is made from a quarter ounce of Captains Cake. It looks like this because I took the pic after I took it out of my regular oven (not vacuum oven) it was about to go in the vac oven
After I filter with the buchner I do a rotovap then I put that in the regular oven @ 180°F for 80 mins scrape into a glob then I put that into the oven again for another 80 mins then I scrape that up and vacuum purge @ 86.5°F for a day or two usually comes out just fine.
I have seen @cyclopath make some pretty nice ethanol shatter. The color was still a bit darker than one would see using hydrocarbons to extract. He can speak more to his process, providing he has time to respond. I believe the trick lies in temperature of extraction, quality and freshness of biomass, and keeping the residence time as short as possible. 15 minutes is too long. One pulls too many chlorophylls with longer residence times when extracting with ethanol, leaving the crude such dark green it appears red.
I also know that the CUP 15 claims to be able to produce the elusive golden ethanol extraction. The trick using their fuge involves misting the ethanol over spinning biomass and allowing the ethanol to immediately run off. There is no second pass, and the yeilds will be significantly lower.
Im using the ethanol denatured with heptane avalaible from carbon chemistry.
I saw that anything stored with a humidity regulating bag made dark extract almost everytime.
I think freshness is a factor after about 4 months, if the bud was dried and stored properly.
Im not sure if the silica is acting as a dessicant, i primarly use it as a filter aid to guarantee i dont have to take apart the column to fix the clog. I did one run of some fresh frozen that has been in the freezer for a year and was just as good as fresh dried trim.
I think you need to break up those nugs to really get in there so that the water doesnt trap any of those goodies. I havent done side by side extractions of unbroken bud and broken up bud, but it was just a hunch i stuck with
This is an interesting proposition. Not once have i been able to make a stupid fire extract with those bovine humidity bags in the stored material. Hmmmm. I think i need to start talking to the people that insist on bagging their material with those. Thanks! Gonna get back to you on this. This is the first time ive ever heard this as a possible cause for darker extracts.
You definitely can! First things first cold aint cold enough for ethanol extracts until you get in the -80’sºC. I use 195 cane ethanol at -84ºC at the warmest. Aside from temp and Ethanol source/quality it is very important to minimize exposure time. Don’t worry about not extracting everything and leaving Cann’s behind. Ill get to that in a sec. Keeping it cold all the way through filtration is also helpful so filtering below 0ºC is a solid bet. I also recommend a slower evaporation keeping your water bath as close to ambient as possible, we do 30ºC. 85ºC is hot and will for sure darken your extract. To maximize your returns after your initial cryo extraction immediately rerun the biomass at a warmer temp for a longer time (room temp for 10-15 min should get the rest out). Obviously keep this second run separate. I typically winterize and carbon scrub the second run to get ride of all the waxes and chlorophyl. You will also pick up a good amount of water from rerunning at a warmer temp so pack a ton of sieve in your filter during your last filtration step to remove the water before evaporation.
You need to filter through a cake of bentonite clay topped with a layer of activated carbon in a Buchner with vac assist. I extract in a steel bucket and I get golden extract pretty consistently with proper SOP, filtration, and adsorbants. Both of those products can be purchased from @Shadownaught at Carbon Chemistry. The bentonite is sold as T5.
Below is some of my recent ethanol shatter.
I’ve gotten some beautiful bright yellows, and light ambers, when extracting premium material, but having never scrubbed my extracts before hitting the oven, I’ve never gotten anything close to what @TheLostBiologist is showing above.
The key is modulating the temperature of the extraction system - and by system I mean something as simple as solvent, a bucket, and a mesh bag.
If you can get the solvent down to -80 C, that is a good place to be. You need to allow the solvent to “warm” up to -50 C or maybe -30 C. If you attempt to keep the solvent at -80 with minimal flow/stirring you will get very small yields (less than 5%) but nice product. Ramp up to -50 C and then stop and you will get favorable yields and still great product.
At -80 C there isn’t enough kinetic motion on the molecular level for effective dissolving of cannabinoids, also introducing some “flow” into the solvent will help the process.
The bentonite does a terrific job of removing water soluble contaminants. It’s great for removing denatured proteins and unwound DNA that come along with the EtOH extraction. It even helps a bit with chlorophyll contamination. The AC is a great general adsorbant but in this case is used for decolorization.
There is always talk about AC absorbing cannabinoids. I haven’t seen anything in our testing that suggests that it has a significant negative impact on final concentrations. In fact, we typically see a bump in concentrations after carbon use. So, if it is removing cannabinoids it’s at least removing everything else at a faster rate. The end result is a higher final concentration. At least with our SOP. There are a lot of ways to use AC and I haven’t tested most of them.
what evidence do you have that ethanol is extracting DNA?
As a Molecular Biologist, I have isolated a LOT of DNA over the years. Getting the DNA out of plant cells is non-trivial. grinding after freezing in liq N2, and extracting with an aqueous based solvent (alkaline lysis), or another organic solvent (phenol/chloroform). Both ethanol and iso-propanol can be used to precipitate DNA from aqueous extractions, I would not expect either to pick up significant DNA during a properly done (cold, not ground below 1/4") extraction.
Given that I haven’t actually looked for it, I’m not certain it isn’t there, but it’s not something I would expect to find, and am curious…
I’ve made small batches of ethanol extract that was accepted by the community as a relatively decent product. Generally, as others have said, cryo conditions were key.
We did a series of simple soak extractions to observe the rate of chlorophyll and other darker pigments being dissolved into the solution. We found that when soaking fresh, cryo frozen flower in chilled ethanol (around -70C) the solution began to pick up darker pigment after 48 hours of soaking.
I’ve included a picture of some “pull and snap” made with a 30hr simple soak and vacuum purge, no other post-processing techniques were used.
From what I’ve experienced and seen, it seems ethanol extracts can be more difficult to scale than hydrocarbons, though many states make hydrocarbon extraction difficult to utilize with ppm recs.
@cyclopath Pure supposition. When I first came on at this facility the post processing was minimal and rudimentary. The SOP was also much different. The extractions they were doing at the time were much warmer. The coldest they got was about -10c, straight from a commercial freezer. At the time we were seeing significant precipitation of water soluble contaminants both during rotary evaporation and durring subsequent decarboxylation (for decarb oils). They stuck to flasks, burned on to beakers, and smelled and tasted atrocious.
At first all we knew about the contaminants was that the only way to get them off the wall of a flask was to wash them with warm water. While they would resist ethanol washing they would come off quite easily with warm tap water. Hence, we began describing them collectively as “water solubles.”
After doing some research on what they might be I honed in on denatured proteins and unraveled DNA. My assumption was not that the ethanol was absorbing the DNA but that the ethanol was carrying water from the extract, bringing the contaminants along for the ride, similar to chlorophyll micelles. Our theory was that the water we picked up in the extraction (which was a lot due to the temps we were running) was leaving behind the water solubles as it was purged away both azeotropicly with the ethanol in the rotary evaporator as well as boiled off durring decarb.
As I understand it ethanol precipitates DNA not due to insolubility but by reducing the amount of water available to hydrate the DNA. This concentrates the DNA into the remaining water, causing precipitation. This would seem to fit with what we observed in that as the water content fell we saw greater and greater deposits on the flask/beaker.
Long story short, we picked up the bentonite to help deal with the water solubles we were seeing. It was a dramatic difference. We have since greatly evolved our extraction SOP. We run much colder for much less time. I would surmise that alone would mitigate the water soluble issue by way of simply having less water picked up during extraction. However, beyond working well for water solubles the bentonite also provides a terrific fine filteration media. On the basis of “it ain’t broke, don’t fix it” I have not attempted to make an oil with just the new SOP. Whether I have water solubles to remove or not it sure does make the oil shiny.
