Eisbock, an extremely strong beer with a typical alcohol content well beyond 7% ABV. This beer undergoes a freezing process called “freeze distilling” that separates water from the other components (alcohol and sugars) to concentrate these. Water has a lower freezing point than ethanol, so the water freezes, leaving the alcohol liquid. When the water ice is removed, the remaining beer is stronger than before. The style seems to have originated in Franconia, reputedly in Kulmbach. The local Reichelbräu brewery (now part of Kulmbacher AG) claims that an apprentice was ordered to move a barrel containing bock beer into warmer parts of the brewery on an especially cold winter evening in 1890. He failed to do so and by the next morning much of the beer was frozen. The ice inside the barrel had extended to a degree where the wooden staves eventually broke. When the head brewer returned to work, he found the barrel busted and a block of ice encapsuling a small amount of dark liquid. This liquid proved to be far tastier than expected: the eisbock had been invented by pure coincidence. This is at least how the story is told in Kulmbach. Interestingly, however, it does not appear in any of the German brewing books of the time. Reichelbräu put their eisbock on the market and “Kulmbacher Eisbock” (also dubbed “Bayerisch G’frorns” meaning Bavarian ice cream) is still one of the few commercially available beers of the style. Another fine example is the “Aventinus Eisbock” by Weisses Bräuhaus G. Schneider & Sohn, aka Schneider Weisse, where the basic beer used is “Aventinus,” a weizendoppelbock. Many craft brewers have enjoyed experimenting with the production of eisbocks and other freeze-distilled beers, with some of the beers reaching ABVs of over 40%.