A few months ago I brewed an imperial stout, OG 1.104. I left it in primary for a month and it's been aging in a carboy ever since. When I transferred it to secondary, it was still a few points high (around 1.034). Since racking to secondary, the fermenter has been bubbling steadily for about 8 weeks. I checked the gravity today and it's around 1.020 -- over 80% attenuation.
For the record, my grainbill was fairly complex (82% MO, 6% roasted barley, 4% chocolate malt, 4% flaked oats, 2% special B and 2% midnight wheat), I mashed at 154 for 90 minutes and pitched a 4L starter of WY1728. I just do not understand how I achieved such high attenuation, and why it's taking so long to ferment. The only thing I can think of is maybe my yeast mutated (this is the 5th generation I believe)...there's no evidence of infection or off flavors present.
Has anyone else ever experienced such a long latent fermentation (without using bugs)?
For the record, my grainbill was fairly complex (82% MO, 6% roasted barley, 4% chocolate malt, 4% flaked oats, 2% special B and 2% midnight wheat), I mashed at 154 for 90 minutes and pitched a 4L starter of WY1728. I just do not understand how I achieved such high attenuation, and why it's taking so long to ferment. The only thing I can think of is maybe my yeast mutated (this is the 5th generation I believe)...there's no evidence of infection or off flavors present.
Has anyone else ever experienced such a long latent fermentation (without using bugs)?
