Borrowed from German trüb (“not clear, turbid”). Related to droff (“turbid, sorrowful, sad”)), Dutch droef (“sad, miserable”).

trub (countable and uncountable, plural trubs)

1. (brewing, uncountable) The layer of sediment that appears at the bottom of the fermenter after yeast has completed the bulk of the fermentation.
2. (obsolete) A truffle^[1]

• droff

• Burt, brut

• IPA^(key): [ˈtrup]

trub f

1. genitive plural of trouba