I've been having problems with how beer as well as other things have been tasting for about the last 18 to 24 months and I think I may have nailed some of the cause(s) down.
2 years ago I had minor sugery which required enima's etc... complete bowel elimination. Shortly after that I started noticing astringent off flavors in beer, commercial and homebrew.
Since then I've undergone surger two more times and each time my tastebuds become "hypersensitive" to certain things. I don't know if it has anything to do with the clean-out preparation and or the drugs during surgery as well as after or what but each time the "preparation" has been different and each time I've become hypersensitive to something else or different.
I also quit smoking 5 months ago.
My most recent "hypersensitivity" seems to be sweetness... now sweet things seem to be too sweet. I mean come on... a LifeSaver is a LifeSaver isn't it... well now they seem way too sweet to me.