« on: July 12, 2015, 04:40:56 AM »
The low pH should inhibit bacteria, but won't necessarily prevent it from taking hold. Also, mold can be an issue - this year is particularly wet in my area (Northern Illinois), so the mold counts are way high. We don't brew in totally aseptic conditions, especially in the summer when airborne contaminants are rampant. Try your best to limit contact of the wort and beer to air exposure in the transfer processes. Bacteria and many other nasties love oxygen and at the point of packaging, oxygen is not your friend. Kegging works great in this regard, because you can start with a keg that has been CO2 charged for a blanket of CO2 and then rack to the bottom of the keg to protect the transferring beer somewhat. If bottling - try bottling off the keg and purging each bottle with CO2 before filling with beer. Coupled with meticulous sanitation, you will likely avoid significant problems. Last thought - were you re pitching yeast from a prior batch? The same issues are present relative to re-using yeast and limiting exposure to the airborne contaminants when harvesting, storing and re-pitching.