Good afternoon. Recently, two of our beers seemed to develop an off-flavor. The first, a red made over the summer, developed what my wife and I both thought was quite a strong off-flavor, nearly a dumper. I do not have a very sensitive palate, so it can take me a while to decide what it tastes like. It could be a sour flavor (lacto infection?), but I don't think it screams sour, it is more subtle than simply a sour apple or similar flavor. I might describe it as medicinal, which maybe could come from chloroamines in the water? (That is what our municipality uses). I gave some to my father who is a long time beer drinker and brewer, but he didn't seem to notice anything wrong.
We made a second batch, a steam brewed Octoberfest, which had a subtle undercurrent of something wrong when it was green, and then seemed to mature to a nicely drinkable state about three weeks after bottling. However, this last week (four to five weeks after bottling), the bottle I tried again was tasting maybe a bit sour, maybe medicinal - something! It was overwhelming the hops and the malt and was the dominant flavor both at the finish of a swallow and I thought in the nose as well, but only on the swallow, not on just sniffing the beer.
These are my thoughts on possible sources:
- High fermentation temps: we had not yet implemented a swamp cooler and I think the red was probably in the 80s at some point while it was brewing (this was late summer North Carolina)
- Chlorophenols from chloramination in the water supply: quite possibly, but we had made 10 batches previously and not noticed this problem
- Sour beer from an infection: possible. Both of these batches were made with equipment that had been sterilized in bleach at the tablespoon per gallons level (we had not yet switched to star san). Maybe a bug got in on a scratch or in a valve? We use plastic Ale Pails
- Poorly sanitized bottles: our bottles go through the dishwasher with a sanitizer. However, again we've not had this problem and the red, especially after a few months, had the same strong off-flavor in every bottle
Thank you for any insights. I currently have a Best Bitter in our newer Ale Pail about ready to be bottled, made with spring water, and a dubbel in brand-new Ale Pail where I controlled the fermentation temperatures very tightly, so maybe one of these two batches will shed light on where the problem may have entered. I wish I could describe or understand this flavor more clearly, though.