Moving into the malt-beverage world, brewers in Germany use fractional freezing to make eisbock. These brews are usually just regular bock beers, which clock in at 6 percent ABV, freeze-concentrated to something in the 13 percent ABV range. Frankly, there are probably easier ways to get high-proof beers (make a barleywine, for example) than by starting with a mid-strength one and concentrating it, but there's a market for eisbocks and it's possible to find them in the US as well. A more infamous set of freeze-concentrated beers was made by the Scottish brewery BrewDog in their quest to make "the strongest beer in the world." The first was Tactical Nuclear Penguin, a beer that started with an ABV in the teens and ended at 32 percent ABV. Then a little brewing war started up between BrewDog and German brewery Schorschbräu to make ever-stronger beers. Schorschbräu made a Schorschbock at 40 percent ABV, BrewDog countered with Sink the Bismarck at 41 percent ABV. Then came another beer at 55 percent ABV (that's 110 proof, my friends). Schorschbräu is current record-holder with Schorschbock 57, at 57 percent ABV.