How high in alcohol can a beer beverage reach and still retain its flavor? The answer is somewhat dependent on how we, or actually the omniscient U.S. Treasury Department’s Alcohol and Tobacco Tax and Trade Bureau (TTB), defines beer. In Europe, especially Germany, beer schnapps is widely available, liquor distilled by breweries from their own beers.

In the U.S., breweries cannot distill without a separate distilling license and facility, and no current breweries make a beer schnapps. Clear Creek Distillery owner Steve McCarthy makes his Oregon Single Malt Whiskey from a fermented Scotch peat malted barley wash (unhopped beer) provided by Widmer Brothers brewery. He describes his 52.5% alcohol by volume (ABV) whiskey, which retails for $50, as "a very Lagavulin-like scotch flavored whiskey."

Marko Karakasevic, an creative 13th generation distiller at the family’s Charbay Distillery in northern California, has developed a 49.5% ABV whiskey called Marko K’s Double and Twisted Light Whiskey that directly uses an India Pale Ale as the base for distillation. Charbay’s original venture into beer distillation began with an impressive 20,000 gallons of pilsner, distilling it by 20:1 into their Charbay Whiskey, a 55% ABV brew. Charbay says that "There is no other whiskey out that you can really taste the beer that it's made from. The spice from the hops and the barley flavors are very well balanced with just the right amount of oak."

Two American breweries currently also distill spirits. Rogue President Brett Joyce finds the idea of making a beer schnaps "very interesting" but has never tried. Delaware’s Dogfish Head brewery experimented using its Aprihop as the base but, according to owner Sam Calagione, "the result was too bitter." Calagione says he may try again with a less bitter base beer.

The highest reported alcohol beer currently available anywhere is the dangerous 31% ABV Schorsch Bock 16, made by the Eisbock process in Oberasbach, Franconia, Germany by the Schorschbräu brewery. Because water freezes before alcohol, bocks can be frozen and the remaining ice or slush removed, leaving a the more alcohol-concentrated Eisbocks. The TTB defines any reduction of more than one-half of one percent alcohol to be distillation and therefore Eisbocks are not permitted on a brewery premises in the U.S.

A few small American breweries have made Eisbocks for educational or testing purposes. One in the upper Midwest brewed such a beer almost four years ago, making100 barrels of a 7.5% ABV double bock and plummeting the temperature in its tanks to six degrees below zero using glycol cooling, and then "removing a massive Sno-Cone". The resulting 75 barrels of 10% ABV beer tasted delicious according to the brewer.

Expanding the process in the early 1990s was a Pacific Northwest brewer who delightedly observed how locals made Apple Jack, by putting cider outside during the winter and letting the cider freeze time and again, sometimes up to six times, with an end result of only 20% of the original volume. Repeatedly freezing his ale, the 300 gallons of 10% ABV original brew was frozen three times, with a reputed end result of 90 gallons of 29% ABV. The brewer thinks he could have repeated the glacial freezing several more times. He says that the beer was "originally hard to drink but has smoothed out and mellowed with time. It now has port and sherry character with notes of dark fruit." The beer is not available for sale but used for educational purposes.

In the last few weeks BrewDog, a cutting-edge Scottish brewery located in Fraserburgh by the North Sea, has released Tactical Nuclear Penguin which the brewery claims has 32% ABV so the upper limit for an Eis-beer may be changing.  This imperial stout ale was made by freezing the beer for three weeks at 20 degrees below zero in a local ice cream factory and continuously removing the ice.

The highest alcohol, traditionally brewed beer available in the U.S. is Boston Beer’s Samuel Adams Utopias which has reached 27% ABV for the two latest versions in 2007 and 2009. About 10,000 bottles of the complex 2009 Utopias were released in November with a suggested retail price of $150 for the copper-clad, brew kettle shaped 24 ounce bottle. This Utopias batch is blended from beers aged in Scotch whiskey barrels and single use Bourbon casks from Buffalo Trace distillery. It is then finished in Spanish Sherry casks, Portugese Port and Muscatel Casks. The 2009 release "tastes close to Port" according to Jim Koch, president of Boston Beer, "while the 2007 release had more cognac character."

Most high alcohol brews, including Utopias, are made using a regimen that includes using multiple yeast strains fed frequently with simple sugars including Belgian candi sugar, brewers sugar and beet sugar. The yeasts are oxygenated, often by aeration, to provide the tiny beasties with a growth environment, agitated to keep the yeasts frisky and in suspension, and fed when their fermentation slows. For Utopias the yeasts are pulled and the survivors are recultured and reintroduced. Some brewers use the White Labs Super High Gravity Ale Yeast which, according to the White Labs website, can ferment beers up to 25% ABV.
Each brewer has some additional tricks. One homebrewer who claims to have brewed a 20+% ABV beer even used Beano tablets to break down unfermentable sugars into fermentable ones.

After Utopias the next highest traditionally brewed beer is Colossus, by DuClaw Brewing of Baltimore, MD, which is being released in very limited quantities in Maryland liquor stores. Colossus reached 21.92% ABV from a lab analysis done by Siebel labs. Brewer Jim Wagner thinks he can reach 23-24% ABV in a future brewing based on his lessons learned and the 25% reached by the high gravity White Labs yeast he used.

Colossus undergoes a primary fermentation of about two weeks, reaching approximately 17% ABV and a secondary fermentation using many of the noted techniques plus adding an enzyme to break down the complex sugars. The beer was brewed in 2005 and has been aging since that time. Wagner regales that "Colossus now tastes like a combination of ale, mead and port with dark fruit flavors. When young it had hints of peach, apricot and coconut."

The brewery with the largest assemblage of high alcohol beers is Dogfish Head of Milton, DE. At one point when Dogfish’s World Wide Stout reached over 22% ABV, as did Raison D’Extra,  the brewery competed for the high alcohol beer record with Boston Beer. These beers both have been scaled back to 18% ABV because, after aging, "In brewery taste tests the 18% versions tasted. better" according to Dogfish owner Sam Calagione. The brewery makes other high alcohol beers including 120 Minute IPA (18% ABV), Fort (18% ABV), the world’s highest alcohol fruit beer, Olde School Barleywine (15%) and many in the 10-15% ABV range.
Boston Beer’s Jim Koch notes that Utopias is a blend of many beers, some in barrels reaching 29% ABV. Koch believes that 29% is probably the highest level achievable under normal brewing conditions without a breakthrough because "No yeast can protect itself from the ethanol penetration of its cell walls at that point so the cell structure breaks down." That seems to be the current limit for traditionally brewed beers.