The batch in question didn't have what I considered a 'blatantly obvious' infection. It just seemed to go crazy on the carbonation at a point (2 months post bottling) that I did not expect. It also gained what I considered an off, somewhat metallic flavor that wasn't the flavor I had ben getting. Interestingly enough, it was the 2nd in a series of 3 test batches of the Northern Brown style. The first was an extract w/specialty grains, second was all grain and the third was bottled today, an all grain with a bit higher amount of specialty grains and liquid yeast. The first 2 used the same fermentation, yeast (notty) and carb level. Batch one turned out nice and has not exhibited any unusual activity. the second one started out OK up to 6 weeks post bottling but then started the excess foaming. I still have a few bottles of batch 1 that are good. If anything has come of this, it has pushed me to a new cleaning/sanitation regime. If it touches my wort/beer on the cool side, it gets PBW/oxyclean post use and a good soak in Starsan prior to use.