Kellerbier (literally “cellar beer”) is an unfiltered, unpasteurized, very yeasty, malty lager from Franconia in central Bavaria, where it is still a summer favorite in local beer gardens. It is usually drunk out of earthenware mugs rather than glasses. An authentic kellerbier should be strongly flavored with aromatic hops and brewed to a märzen strength of about 5% to 5.3% alcohol by volume. More often than not, a kellerbier is deep amber in color, perhaps with a reddish tinge, as the result of a good portion of slightly caramelized malt in the grain bill. If brewed true to style, a kellerbier has very little effervescence, because traditionally it was matured in wooden casks “ungespundet” (literally “unbunged”), with the yeast still active. As the yeast fermented the remaining sugars in the beer and converted these to additional alcohol and carbon dioxide, the gas was allowed to escape through the bung hole. A kellerbier was finished very dry with both noticeable hop and malt notes in balance. The bung (“spund” in German) of the cask was fitted only for shipping. If tapped under atmospheric pressure, therefore, a traditional kellerbier had virtually no foam. In this it bears some textural resemblance to British cask-conditioned ales. Nowadays, kellerbiers are invariably fermented and conditioned in closed stainless steel fermenters, especially when they are bottled or kegged for shipment to distant markets. They also tend to contain less alcohol than in the past and may even be mildly filtered to remove some of the beer’s natural cloudiness. Enthusiasts, especially in Franconia, feel that kellerbiers make great aperitifs when served to stimulate the appetite before dinner.

See also bavaria, cask conditioning, and märzenbier.