Steam beer

Steam beer is a highly effervescent beer made by fermenting lager yeasts at warmer ale yeast fermentation temperatures. It has two distinct but related meanings:

Historic steam beer, popularly associated with San Francisco and the U.S. West Coast, was brewed with lager yeast without the use of true refrigeration (by ice or mechanical means). It was an improvised process, originating out of necessity, perhaps as early as the Gold Rush and at least 1860 in Nevada. It was considered a cheap and low-quality beer, as shown by references to it in literature of the 1890s and 1900s.

Modern steam beer, also known as California common beer, was originated by Anchor Brewing Company, which trademarked the term Steam Beer in 1981. Although the modern company has corporate continuity with a small brewery which has made beer since the 1890s, Anchor Steam is a modern craft-brewed lager. The company does not claim any close similarity between its present-day product and turn-of-the-20th-century steam beer.

There have been various explanations for the use of the name "steam beer". According to Anchor Brewing, the name "steam" came from the fact that the brewery had no way to effectively chill the boiling wort using traditional means. So they pumped the hot wort up to large, shallow, open-top bins on the roof of the brewery so that it would be rapidly chilled by the cool air blowing in off the Pacific Ocean. Thus while brewing, the brewery had a distinct cloud of steam around the roof let off by the wort as it cooled, hence the name. Another explanation is that the carbon dioxide pressure produced by the 19th-century steam-beer-making process was very high, and that it may have been necessary as part of the process to let off "steam" before attempting to dispense the beer. It is also possible that the name or brewing process derive from Dampfbier (literally steam beer), a traditional German beer that was also fermented at unusually high temperatures and that may have been known to 19th-century American brewers, many of whom were of German descent; Dampfbier is an ale, however, not a lager.

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