One of My Periodic Posts in Praise of Cask Ale
If you want to understand the mysteries of packaging chemistry, I recommend conducting the following experiment. Go to Laurelwood and get a pint of this beer in both forms. They look the same, except that the sparklered cask pour has a tighter, more mousse-like head. It might have been a touch cloudier. But put your nose over the beer and the differences present themselves. The icy keg pour has little to offer in scent, whereas the cask offers a vivid resinous pine perfume. Warmth encourages volatile aroma compounds to lift off the beer.
When the beers enter the mouth, the differences get even more obvious. At 30 BUs, Nail Pale is probably about five too many for a 10 Plato beer. On cask, it's okay, though. The architecture of the malt, mildly sweet, bready, and soft, cotton the hop zing. And the hops, for their part, are full of juicy flavor. The brewers must have added some salts, because it has a London-like minerality that stiffens the finish. On keg, all the flavors are present, but it's as if they beer has been pulled taut so that they're in very sharp focus. The carbonation both diminishes the malt's flavors and soft mouthfeel and sharpens hop bitterness. On cask the beer teeters on the edge of balance but on keg it falls into hoppy imbalance. What feels full and lush on cask seems thin on keg.
Last week we talked a lot about balance and hoppiness. In my comments, I should probably have admitted that the crime of overhopping is far more common than underhopping--at least on the West Coast. That gateway misdemeanor leads to certain felonies, like misusing cask engines. A cask isn't ideal for every beer, and they rarely work with big, hoppy ones. Cask ale is different, but you have to be willing to appreciate the benefits it offers. Souping up hops is not among them. It's only with a beer like Nail Pale that you can begin to see what casks can do for a beer.