Ethanol recovery yield

Hello, I’m new to ethanol extraction so please forgive my ignorance. I have chosen food grade ethanol 190 proof as my solvent which costs me $136 per litre. It’s very expensive compared to other solvents used for extraction but my goal is to make my meds as clean as possible so denatured ethanol and butane are not an option for me and my pockets aren’t deep enough for CO2.

I am going to be experimenting with bucket tek, I have a RE-301 rotary evaporator and a Panda spin dryer as a centrifuge ready to go.

Once again, forgive me… But how much ethanol should I expect to recover per litre of 190 proof going in? And approximately what proof would it be watered down to?

Just looking for a rough idea to get me started on my journey.

I lose about 1lb of ethanol to the biomass for every 10lb of biomass processed. that is not in a panda, and requires an 8 min spin at 1000G. (panda is a hair faster)

and a little more at devol/decarb.

if you’re extracting cold, the bulk of your solvent will still be at 190 coming out of the rotovap.

Why is it that even when retaining proof of alcohol, the extraction efficiency is lowered after several recoveries of the same ethanol?

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Do you have hard data on that?

I haven’t seen a drop-off, and have generally assumed those reporting said drop-off where not checking their proof (and presumably extracting warmer than I do).

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I’ll have some averages by the end of February. It doesn’t help that my switch from one biomass to another coincides with my first recycle of solvent.

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Heptane denatured?

The data I gathered was pre-centrifuge, so there was a lot more fresh solvent being added…and was also for straight ethanol.

I’ll see if I can pry hard data out of one of the labs I helped get running here in Eugene.

I know they saw some strange stuff that seemed to be related to the heptane denatured they chose to run & they have solid analytics at this point.

Actually just 190 proof, food grade. No denaturant, just water.

What’s interesting is, after recovering ethanol about 5 times total, my proof has dropped from 190 to 188 AT WORST.

There is a detectable (olfactory) amount of light terpenes, the same smell most ethanol extractors are familiar with—words won’t really help here.

However, I have been reusing this 188-190 EtOH with nearly identical results each time. Today, I washed the biomass with Fresh 190, once I’ve evaporated this batch I’ll report back.

Regardless, I think it’s about time to set up a redundant molecular sieve—one capturing moisture, aromatics and hydrocarbons (13X) and one regenerating!

Anywho, maybe that long post about Azeotropes has some hidden gems ¯_(ツ)_/¯.


Activated carbon should do a decent job of deodorizing your solvent.

I always figured those terpenes would help with extraction efficiency


I’d assume so as well, after all we are all aware now that terpenes usually act as a cosvent for the cannabinoids.

I’ve heard some answers from some individuals about reuse affecting the polarity of the ethanol/whatever mixture. I’ve also seen quite an obsessive fascination over proofing the ethanol above 190 proof.

Ultimately, the decision making should follow the quantitative analysis, but that shit takes time…I’m getting there. My young brain is very impatient, but I’m gettting there :joy:

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136$ a liter ??? Wtf domperignon or crystal is not needed for this


I’ve reused my etoh more than 5x. It’s always +195 proof after rotovap. It started out as 200 proof food grade.

I check with a proof gauge at room temp (about 78-81*f).

Are you verifying % moisture of the biomass prior to extraction and logging the data?

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All biomass is dried then frozen and kept in deep freezer. Moisture content should be very low.