by db1979 » Tue Jan 15, 2019 3:51 pm
Acetone and methanol will have been removed.
Esters however are formed by the reaction of alcohols with carboxylic acids, both of which are still present in the boiler. The best conditions to form esters are during reflux. So even if you've removed fores and heads, best to discard just a little bit as it will be heavier in esters. There will be esters forming through the run (regardless of whether it was one continuous run, or stopped and restarted) and these benefit from airing your cuts jars. You could minimise these esters by neutralising the pH of the wash as esters are produced faster in pHs lower or higher than 7.