After the first two batches of home brew, I'm in need of some help identifying an off flavor that is persistent in my first two brews, made with two different yeast strains, different malt, etc. Reading about the common off-flavors hasn't helped. I can't tell if it's band-aid, catty, DMS, etc. Having worked in a genetics lab, as a molecular biologist, I am definitely obsessed with sanitation. I doubt there is some bacterial infection in both batches causing the problem. I am anal about sanitation, using a detergent to clean all the equipment, AND using Star San as a final rinse. However, unbeknownst to me, the powder detergent I bought with my kit was chlorine based. I bought it thinking it was an oxi-clean type powder, but I have suspected it was bleach from the smell (the ingredients are not listed on the package). I have two possible theories about the of-flavor: 1. The chlorine cleanser, which I rinse with (chlorinated) tap water perhaps permeated the plastic fermentation buckets sufficiently to react with the fermenting beer to cause chloro-phenols to show up. I use bottled water for the mash, so the source of the chlorine would be the sanitizer and the tap rinsing water. 2. Both of my first batches fermented in a building cellar that does smell very musty. My initial thought going down there to set down the fermenter was that this could become a problem, especially if the bucket is sufficiently porous to allow the musty, mildew smell in the air to make it into the fermenter. Now, for both of my first two batches, the smell/taste of the fermenting wort at about two weeks into fermentation was great. I only began to detect an "off-flavor" in it after the 14 day mark in primary. It was mild at first, and intensified about 5 fold after bottle conditioning. It definitely became more pronounced after a week in the bottle. I have a hard time identifying it. I can't tell, it it's baid-aid, catty, wine cork, or what. I'd hate to keep doing the same thing expect a different result. If there is someone (preferably in Europe) with experience identifying these things, I'd love to send you a bottle of this latest batch so I can get some help identifying and solving the issue.