Their Sink the Bismarck was 41%, if I recall. Like TNP, it falls into the interesting category – I wouldn't drink a pint. To be fair to Brewdog, they do brew some great beers and their publicity seems to work, it's pretty easy to get a Dead Pony or Punk IPA even in places that would have previously offered Fosters, Carling, or if you felt a bit special, Stella. I'm minded we should celebrate them as a successful British/Scottish business. They do some genuinely great beers, share all their recipes, seem pretty fair to their staff, and when they're caught being dicks about stuff seem willing to stand up and admit they're being dicks and say sorry.
Quite a few imperial stouts and barley wines are 10-15%. In fact, I had a bourbon-barrel-aged barleywine from Brewdog that was 17% and completely lush and I probably could have drunk a pint, if it hadn't been my first drink of the day.
Different yeast strains have different alcohol tolerances, they usually only die between 14-18%, but their metabolism drops off sharply as the alcohol content rises, hence strong beers having to sit around for a long time to make up those few last per cent.
