Originally Posted by cubbies
Your water chemistry can cause it. Unfortunately that is the extent of my knowledge. I forget what chemical causes it, and I couldn't tell you what a high portion of that would be. I am pretty sure it is in how to brew though.
I get a slight metallic aftertaste in some of my beers that use darker malts. I'm certain it's a water chemistry issue. I'm getting a water test, but in the mean time I just keep making APAs and IPAs, etc.
Do you notice it more it a beer with darker color malts, particularly roasted malts?