I mostly meant that the silicone bung lets in a lot more oxygen than an airlock. The Better Bottle measurements showed 14x as much oxygen ingress on a solid silicone bung as on a standard airlock. I would expect that a silicone stopper that was designed to release air would be even more...
Thanks!
I think doing this with a Fermonster would be a good idea if I was starting from scratch. (I actually have a Fermonster with the ball lock post lid that I use when I do fruit additions; it's a good setup.) But cost-wise getting a Fermonster with a solid lid and adding the ball lock...
I have a few glass carboys that I use to age sours or other mixed fermentation beers long-term (6-18 months). In the past, I had used a standard airlock with a drilled rubber stopper. Last year, I wasn’t checking on them regularly, and one of the airlocks went dry. By the time that I noticed...