I brewed a american nut brown ale in Feb. did the 1-2-3, and have been enjoying a beer afterwork for a couple of weeks. Last night, my beer had quite a bit more head and a slight off odor to it, taste was alittle different but not bad. I just think it might have been that particular bottle. If I happen to open another this evening and it has the same off smell,what could it be? like I said I have enjoyed the previous few with a problem. Would bacteria growth be showing/tasting/smelling this late? This is my first brew, so I'm new to the changes my HBs will go through, any advice will be helpful and appreciated.