Stout went from amazing to....odd

[Zinger1]

I did the black rock Stout awhile ago. Bottled in late August/early sept.
Up to and including 2 weeks ago it was absolutely perfect, amazing taste and well carbonated. Had an Oktoberfest at my house over the weekend so I was doing flights of my own stuff for guests to sample.....
Every bottle of stout I opened now all have a peculiar, not good, Smokey taste to them. What the hell happened!? Any tips?

 

[TandemTails]

sounds like some kind of infection. Some brettanomyces can produce smokey flavors. Were the beers extra foamy when you opened them?

 

[Zinger1]

They had a decent amount of head if poured right. Thing I’m having trouble figuring out is why for a full month they tasted spot on, then poof! I haven’t cracked any from the second case yet but my hopes aren’t very high

 

[cyberbackpacker]

Some bacteria are slower reacting agents compared to brewer's yeast, hence the reason why it may have tasted good eventually, but is now giving you weirder flavors.