Beer Forum

Should a carboy cap not be used during secondary fermentation? It looks to me that it isn’t at all air tight compared to a rubber stopper.

My cap is the really tight and i use it for both primary & 2nd. No probs so far.

dosen't have to be that tight really.... you aren't going to get that much air transfer.
Mine is tight enough to make a bubbler bubble but I can rotate it on the lip of the carboy without much friction.
BUB