We have a new brew group in my hometown and had our first tasting evening yesterday. There were quite a few mediocre beers of the dark inclination to be tasted, and I was shocked by the fact that I was totally unable to describe what the problems were. I went over the list of off-flavors, and could not really detect anything jumping out. Like off-flavors blended together... What I think most of these beers had in common was some unpleasant, rather harsh bitterness especially when tasting the beers retronasally. They all seem to have something in common - certainly an absence of crispness or freshness, but to describe what actually is wrong with them and to make suggestions as how to improve them was beyond me...
Any ideas? What these beers have in common is that they use our local tapwater, but with 185 ppm bicarbonates and nothing else really wrong with it, it's not the worst water in the world, especially for brewing dark beers. Or is it?