I have noticed this a lot, and just have gotten around to asking the question. Why is there a higher ABV for beers when they are barrel aged vs. the base beer. Is it because the brewer's add extra yeast to cause further fermentation in the barrels....(wait, me thinks exploding barrels, so no.) Is it live yeast still in the beer? Doubt it... (maybe a small amount, but again exploding barrels). I highly doubt it picks up residual alcohol from the barrel (if that's even possible). So why the difference in ABV??? I truly hope it's not due to a different base beer, because that would make every BA vs. Base beer tasting null and void if the ABV was different. Help me out here, o knowledgeable BA's.