I once had the opportunity to have some unaged Georgia Moon corn liquor. It was quite the experience. In particular, a certain sort of nasty flavor that I don't really have a good description for besides "rancid something" burned itself into my brain, and since then, I've noticed it cropping up as an undernote in certain bourbons and ryes. Most recently I noticed it in Old Overholt.
I don't notice it in all bourbons, so I'm guessing it's a fault of some sort, but I suppose I haven't spent enough time with bourbon to really say anything helpful... Any clue what I might be talking about, or what it's called, or how it got there???