Deja Vu. OP, I was just telling someone in a different threat that same basic story about my past brewing experience. I found 14 yr old stout in Grolsch bottles. I chilled about 5 of em and have opened em up on each of my recent brew days. Maybe a strange offering to the brew day god. They were still carbonated and still tasted like stout. The flavors had diminished, but were still drinkable. I was OK drinking it, but I don't think I should serve it to anyone else.