One advantage to drying and decarbing biomass before it enters EtOH extraction is that water is a non-issue and the EtOH picks up very little water.
In a recent run of my mini extractor, I reused the EtOH three times and ended up with 93 proof ethanol after rotovap.
Mini Extractor for Personal Use
At this level, EtOH is easily re-proofed with type 4A molecular sieve beads and is ready to go again after filtration.
Nobody has much data on the solubility of cannabinoids in EtOH azeotrope at low temperatures but I think it is at least 50 mg/cc at -20 where I run.
That means that I should be able to dissolve 50 grams in a liter and this is consistent with what I see using my extractor, even the first of three aliquots of EtOH is not saturated after three passes.
The third aliquot on the third batch still looks pretty clear.
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