Well a few months back my buddy James and I brewed a Rye Mild. The brew went as planned, except for the fact that I forgot that I didn't have an open fermenter. No problem I said, we'll transfer my Mo' Betta Bretta clone out of its Better Carboy into some 4-liter jugs, sanitize the fermenter and put the rye in.
So we gave the Better Carboy a soak and scrub with hot water and OxiClean making sure that all the little bits of yeast gunk were gone. Then we gave it an extended soak, 30 minutes, in Iodophor. The beer fermented fine, and tasted as we expected for about a month in the bottles... then it happened.
About a week ago I cracked a bottle a got a slight Brett C fruitiness, must be a dirty glass or an off-palate, sadly a bottle the next day tasted the same and finally James confirmed my thoughts. Maybe it was the fermenter maybe it was some the the crevice or crook of some other piece of equipment harboring the invader, but it really doesn't matter now.
Here's the thing, the beer is now different, but still damn tasty. It's strange the beer doesn't seem to be building up much extra carbonation either. Only time will tell if this turn into a low-abv Flanders Bruin or a horrid gushing drain pourer.
As soon as I realized what had happened I gave every piece of brewing equipment I own (that ever touches beer post-boil) and gave it 6 hours in a heavy bleach solution followed by a full dry and then a soak in Iodophor.
Luckily either of the two beers I have done since then is showing signs of Brett activity, but they are both pretty young.
I guess this is a wake-up call to start taking sanitation and segregation more seriously, either that or stop brewing anything but wild beers...