Cleaning persistent bug
Anyone have any suggestions for clearing a house of what looks like a persistent pediococcus infection?
I have been brewing at a friend's house, and it seems that the house itself is infecting our beer. Here's how I'm coming to that conclusion.
We brewed about four beers there that came out super clean back in June, and about a month later we started getting a nasty sour accompanied by lots of diacetyl, haze, and, a foul, rubbery bad yeast odor in everything we brewed there. Also had a very vigorous fermentation but LOTS of ropes and little to no krausen. At first we thought it might just be way high fermentation temp (a few batches using S-05 accidentally hit almost 80 degrees overnight), but it showed up in every beer after that for months with different yeasts and good fermentation temps.
Sounds like pediococcus, right?
We tried switching cleaners (I usually do a PBW and starsan combination), heavily bleached all our gear, replaced some equipment, chilled the wort as fast as possible (we use a copper immersion wort chiller that takes about 7 minutes to cool a five gallon batch, but started giving it an ice bath as well) - pretty much everything we could think of, but the same infection turned up in every beer for months. It was incredibly frustrating.
Most of our gear is steel, we ferment in glass, and we were getting the bug in primary before any plastic racking canes or other suspect gear came in contact with it. We had been fermenting in his basement, which is old and musty, but with properly fitted and sanitized air locks in place, it seems unlikely that something was getting in that way. That pretty much just leaves the wort chilling stage as the point of infection. I always put the wort chiller in for the last five to ten minutes of the boil and give it a good cleaning between uses, so it shouldn't be the chiller itself.
Finally, we tried brewing a batch at another friend's place with the exact same gear, same setup, and same process, and it came out perfectly clean. We've done a few more batches since then to confirm that the infection is gone, and they're all fine. Doesn't seem like it's the gear.
All I can think is that my friend's kitchen is overrun with a nasty pediococcus infection that was managing to colonize our wort right as we chill it.
We're making good beer again, but it sucks that my friend can't brew at his place.
So two questions:
1) I know it's impossible to say, but am I right in my diagnosis that it's pediococcus and that the house itself rather than a piece of gear is the source?
2) What can we do to get rid of it? He's a very clean person, and we've already tried scrubbing the kitchen down with all kinds of disinfectants, but the house is pretty old.
Any thoughts would be much appreciated.