So, I got a whiskey barrel from a boutique distillery here in Chicago. It had 22oz of whiskey still in it, which kept it wet (it was also kept sealed). I brewed up 30 gallons of Russian Imperial Stout, fermented it outside the barrel, and confirmed no more active fermentation (around 2 weeks)
FYI, 6 5 gallon batches were done
So, I drained the whiskey, transferred the beer, sealed it with a stopper and passed out from exhaustion! Woke up the next day with the stopper popped and fermentation started again! I was under the impression that since I fermented out I shouldn't have had any active fermentation in the barrel...
Was I wrong? Any idea if how much fermentation I should expect?