Does anyone know about any kashrus issues regarding certain beers? I know that most beer is assumed to be kosher, but I have been told by a not-necessarily well informed party that dark beers may be problematic, as brewers will add wine to enhance the color. I've also heard that some stronger beers, aka barleywine, may have kashrus issues, as well as some other imported brews.
Do I have to watch out for this stuff, assuming a fairly strict level of observance? Or is this more like the ersatz problems with Scotch that my (very frum) Rabbi says comes from "am aratzus" (i.e. ignorance) rather than from any real halachic issues.