What's responsible for the "metallic" taste in Belgian beers? Whenever I've had Belgians, I've tasted something metallic, especially in the aftertaste. It was especially strong in Lost Abbey's Judgment Day, a quadrupel. I thought it was something unique to me because no one knew what I was talking about, but today a friend said the same thing ("metallic", without me suggesting anything). What in the brewing process causes this taste?

In case it helps, I also taste it in Killian's Irish Red.
Common causes for a metallic taste are dissolved metals such as iron or copper, either from the water supply or brewing equipment, or due to the oxidation of fat molecules which can bind with metals.  

Personally though, I find that I can regularly taste metal in the finish of any of a variety of beers that are over-chilled.  I don't recall Belgians being particularly an issue (but I love Belgians and am probably more likely to ensure they're properly temp'ed before drinking) but when served too cold, I can almost guarantee that I'm going to get a strong taste of cold steel right at the end of many brown ales, red ales, and stouts among others, and that it will generally disappear as the beer warms.