I brewed a nut brown ale February 16th (partial mash) left it in the carboy 4 weeks then bottled. After bottled it had a good malty flavor with a roasted finish (possibly a bit strong for my taste, but still good). I just opened another one yesterday (and again today) for the first time in a month and it was completely different.
Had a sweet aroma, maybe some plum, and sort of smelled hot. There was no sour/vinegar aroma that I would expect from an infection.
The flavor was tart, maybe sour. It was definitely hot. There was no roasted finish. The beer poured with a good head and had good, actually great head retention but a lot more carbonated than I remember.
I used Wyeast (1272) American Ale II which is a little fruity, but shouldn't overwhelm the finish. I fermented at 68 degrees with no unusual smells and stored the bottles at b/w 66 to 68 degrees.
So: is 6 months in the bottle too long for a Nut Brown Ale? (pretty sure the answer there is no).
Do I have an infection?
If there is an infection, could it have taken place in my primary fermenter and taken almost 6 months to come through?
Luckily I have already drunk all but 5 (now 3) but this is still quite bothersome.
Thanks for your help.