I’ve been recently plagued by several infected batches in a row. It’s starting to drive me insane! My cleaning and sanitizing is (not to brag) impeccable, but I can’t seem to shake this funky wild yeast strain. Everything tastes fine at kegging time then it gets an odd sour taste. I replaced all my tubing, bungs, and everything else plastic. It wasn’t my draft system, because I batch that I had bottled had the same issue. Also, my saison (on tap) was not affected.
Then it came to me one day. I had a bottle of home brewed framboise explode in the freezer and leak down into the refrigerator compartment where I keep my yeast strains. Brett infection. 10 growlers of yeast poured down the drain, a few tears and I was confident I had it beat.
Alas. I tapped my Octoberfest last night which was from a new strain that had not been in the fridge and it has the same sour taste. I’m stumped again. The only thing I can think of is I introduced a new oxygenation system in the early Spring. The bottle and regulator were purchased from a not terribly reliable source. I have one batch in the primary that was not oxygenated. Hopefully I’ve discovered the culprit. I can’t bear the thought of another 10 gallon batch dumped.