So what we generally do is a double pass with the Ethanol. So we bring one bag of biomass in, put in 15-30 gallons of -40 Celsius Ethanol (depending on which machine) and do the agitation and spin dry. Then we bring a new bag of biomass and replace the old one, and run the same Ethanol from the previous run into the machine again for another agitation and spin dry.
I am going to check with our internal analytical lab about testing the Ethanol after it has been used to extract Kief to see how well the Extraction worked on that front, and I plan to look at the Kief bag itself, see if there are dry spots inside.