EtOH extraction with vacuum purge

Rider509

Well-Known Member
When working with any flammable solvents the usual caveats apply; i.e., no open flames, no smoking, no shuffling your feet across a nylon rug, lots of ventilation, and have a fire extinguisher handy. But I'm a big believer in natural selection so if you do something fatally stupid the human gene pool is enriched by your demise, unless you already procreated and then it's too late, so basically, just don't get yourself dead.

1. For this extraction I started with dried and cured flowers and 200 proof Extractohol. I used 9.5ozs total, equal measures of MamaThai Pineapple Chunk and MamaThai ThaiStik.
2. The flowers were allowed to fully dry in our 20% humidity and were then broken up by hand into smaller bits.
3. Both the alcohol and flowers went separately into the deep freezer overnight. The thought behind freezing is to bind the chlorophyll and other water soluble components in a frozen state.
4. In the morning I poured enough alcohol over the flower to cover, gave them a gentle swirl to fully wet them, and placed them back in the freezer. After 5 minutes I removed and gently swirled, and again put them back in the freezer for another 5 minutes.
5. The mixture was then poured through a strainer to remove most of the plant material, and was then strained through coffee filters. I had several jars ready with coffee filters installed to speed the filtration.


6. The resultant extract solution was then placed in a vacuum pot and gentle vacuum was applied to degas the solvent. After all gas was removed a full vacuum was pulled and heat applied via a hot plate which I modified for low temps and a +/-3F dead zone. In a 29inHg vacuum EtOH boils at about 34C. I found that it was best to maintain a slightly higher temperature to maintain the boil due to the violent start of boil as seen in the video below. This system uses a modified cold trap with dry ice and alcohol to condense and capture the alcohol for reuse and to prevent damage to the vacuum pump.

7. After most of the alcohol was removed the mixture was poured into a pyrex cake dish and additional alcohol was sprayed into the vacuum chamber to dissolve any residue, which was added to the cake pan, and then allowed to evap at room temps until thickened.


8. The thickened mixture was placed on a silicone mat and further vacuumed, with no heat, to remove the balance of the alcohol. Once the evolution of vapors ceased the vacuum was maintained for an additional 30 minutes.

9. The resultant resin was then decarbed at 248F for 35 minutes, at which time no more CO2 evolved, indicating complete decarboxylation.

The resultant CCO is a dark golden amber, very viscous, and smells a bit like heaven.

 
Brilliant! Great write up Rider! Very well done my friend. Now I must purchase a vacuum...it’s mandatory.

Questions: when you say “modified cold trap with dry ice” is that the one you wrapped with copper tubing? Did you purchase the trap separate or did that come with the vacuum? I want to build one myself so I may bug you a bit. Is the dry ice aiding in the recapture (condenser?)? Sorry, for noob questions.

Awesome job!
 
Thanks, GT! The cold trap was purchased for this endeavor. I already had the pump and vacuum chamber from working on silicone projects. The original design of the cold trap relied entirely on chance encounter of the vapor with the dry ice chamber to cause condensation of the alcohol. In initial testing much of the alcohol was lost through the pump. By wrapping copper tubing around the chamber it extends contact time and allowed capture of almost all of the alcohol with no resultant alcohol smell from the vacuum pump exhaust. I erroneously reported elsewhere that it only captured about 85% but I'd neglected to account for losses in the QWET process. The dry ice/alcohol bath is key to condensing the alcohol vapors quickly, and keeping the alcohol in liquid form.


 
My next mod will be to pour a silicone liner to fit inside the vacuum chamber. The goal is to allow complete evaporation of alcohol in a continuous process, reduce product loss and recover all of the extract by freezing and cracking the extract off the silicone surface, and to reduce the amount of time spent cleaning the vacuum chamber. A collateral benefit may be reduction of hotspots in the heated surface.

I will also introduce boiling chips to the vacuum chamber to eliminate the bumping (flash boiling) observed in the above video.
 
My next mod will be to pour a silicone liner to fit inside the vacuum chamber. The goal is to allow complete evaporation of alcohol in a continuous process, reduce product loss and recover all of the extract by freezing and cracking the extract off the silicone surface, and to reduce the amount of time spent cleaning the vacuum chamber. A collateral benefit may be reduction of hotspots in the heated surface.

I will also introduce boiling chips to the vacuum chamber to eliminate the bumping (flash boiling) observed in the above video.

Love that idea. Significant reduction in cleaning if you line it with silicone. What is a “boiling chip?” Never mind...I can google. Im smart like that. :p
 
I kinda get what is going on.... A high tech still.

When are you sampling?

I'll def save some back for friends to try. If anyone ever gets close to SE Washington state I hope you give me a shout. I'd enjoy hanging with you guys around the fire pit.
 
I just may do that Rider. Not for the sample either...hanging at the fire pit would be the reason. That, and I could see exactly how you rigged that contraption of yours. :slide:

Naturally I would come bearing gifts.
It better be spiced rum! I don't use the wacky weed. LOL.
Nothing better than hanging around the fire with friends.
edit: oh oh oh... Grandpa Glue clone! Woo hoo!
 
I'll def save some back for friends to try. If anyone ever gets close to SE Washington state I hope you give me a shout. I'd enjoy hanging with you guys around the fire pit.

I was in that area a few years ago for a job possibility. I never knew there was a desert in Washington. That was so weird.
 
I was in that area a few years ago for a job possibility. I never knew there was a desert in Washington. That was so weird.
There's the evergreen side, and the tumbleweed side. Stinky liberal hippies live on the evergreen side.
 
I'm still kind of trying to wrap my head around everything that's going on here, it's pretty elaborate. Let me see if I got this straight...

1. You're putting the alcohol in a vaccum
2. You're then boiling that alcohol ( is this with an additional heat source, or does it just boil at room temp because of the pressure decrease?)
3. The alcohol is then going through a copper tube around a cooler where it's "trapped" in another container almost like a still?

That seems very cool man! I'm guessing by watching the video that your vaccum chamber is separate from the alcohol trap?

I'm a bit slow on the uptake of what's happening here.

So when it comes to alcohol extraction, I tend to go for the 'Less Contact-TIme, More Potency' line of thinking, and like to just pour my alcohol through a sieve containing the plant material, and let it collect in a coffee filter. I'm thinking this would even improve on that method, because with your vacuum chamber you could pull your alcohol through some kind of chamber with a built-in filter and have near instant-extraction, or more controlled extraction time than trying to rely on gravity alone.
 
I use a countertop electric stove that I hot-rodded to get finer control at low heat levels. The alcohol evaps faster when heated to a boil at around 100F. And yes, the alcohol recovery is in a separate cold trap between the vacuum chamber and the pump.
I just ordered a 4000ml Erlenmeyer vacuum flask and a 1000ml Büchner funnel to do just what you described. Quickly getting the alcohol out of contact with the plant material produces a better tasting medication from what I've heard; less chlorophyll and other undesirables.
 
So when it comes to alcohol extraction, I tend to go for the 'Less Contact-TIme, More Potency' line of thinking, and like to just pour my alcohol through a sieve containing the plant material, and let it collect in a coffee filter.
The thing that came to my mind is that it takes time to dissolve the trichomes in alcohol so you may be leaving a large percentage of the THC behind doing just a flush. I think you'd have better yield letting it soak for 3-5 minutes with gentle agitation. If you are going to put the flowers and alcohol in a deep freeze and drop the temps to the 0F range then the soak has to be longer.
 
The thing that came to my mind is that it takes time to dissolve the trichomes in alcohol so you may be leaving a large percentage of the THC behind doing just a flush. I think you'd have better yield letting it soak for 3-5 minutes with gentle agitation. If you are going to put the flowers and alcohol in a deep freeze and drop the temps to the 0F range then the soak has to be longer.
Yeah that's generally why I do a second run, so the first run is the very best stuff. I don't know that it really takes much time for the trichomes to be stripped, because when I find trichomes in the bottom of the coffee filter I've tried smoking them and it's as if they've lost all potency, but if I look at them in the scope they're still mostly in-tact, just shriveled up, as if they've lost the liquid inside of them.
 
I wish there was published data on dissolution times and solute concentration limits. If anyone would like to donate about 50g of pure blonde hash to the cause I'd be more than happy to run controlled tests.
:cool:
 
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