Was able to drink this courtesy of some great local BA's last weekend as part of our tasting group holiday party. Luckily, the 09 was uninfected (I'm 2/2 on that end!). Order of rank for me was 10 09 11 12 10 seemed to be the best blend. The flavors were just so perfectly balanced, and it drank so smoothly. '10 Abyss was a prime example of why this beer is one of the more highly regarded brews out there. 09 was like '10, but a little thinner on the mouthfeel and with a little oxidation. Not "cardboard" oxidation, but the kind that gives you a little added richness to the beer. The flavor profiles were otherwise pretty similar to me. 11 was actually surprisingly tasty. I had it fresh and again this past august. I was not a fan of it either time. I felt the beer was a little too vinous and too much licorice in the blend. By now, however, those characters have either faded or become a bit more muddled in the overall flavor, and its drinking much better. Not up to par with 09/10, but actually a beer I would seek out again (unlike my experience with it "fresher" -- and yes, I know it's got a "drink after" date on it). 2012 was a tastier blend than 2011, but quite hot by comparison. I think when it mellows, it'll be better than 2011.
