As black as midnight, Sierra Nevada already has a winner on its hands in Narwhal, their Imperial Stout. But Barrel-Aged Narwhal raises the bar, mellowing some of the beer's flavors while intensifying others. After aging in Kentucky bourbon barrels, this 12.9% ABV beast has plenty of bark, but very little bite. It's smooth, sweet, and mellow till the last pour. Available nationally, but in small quantities, making it nearly as rare as its namesake.