I hope someone can help me with this issue that I have noticed in some of the beers I have brewed, including my current batch of American Amber. For some reason, the beer seems to develop an "off" flavor, sort of an undesirable (not hoppy) bitter aftertaste when chilled. However, this flavor is not present or greatly subdued at temperatures closer to room temperature. This also happened to an IPA I brewed and at least one other batch I have made. Each batch was brewed with extracts and bottle conditioned for 2 weeks or so before being chilled. Does anyone have any idea what causes this?
Thanks for your help!