I brewed a 1.102 OG barleywine back in June that sat in primary for 3 weeks and then in secondary on oak cubes for 5 weeks. At bottling time, the final gravity was 1.019 (resulting in 11.2% ABV). I was concerned that the yeast might have crapped out by then, so I rehydrated half a packet of dry champagne yeast and added that. Yesterday, 3 months later, I opened a bottle, drank half, and decided to measure FG again. I was surprised to find that it was 1.013. It didn't look or taste like there was contamination, and there was just a bit of carbonation. Could the champagne yeast have chewed through some extra sugars (in addition to the bottling sugar)? If so, why wasn't it much more carbonated?
Any help is appreciated.
