In the world of Czech beer, high-alcohol variants are lost in the darkest arcana. Only a few cognoscenti are aware of Pardubické Porter, a dark beer with with slight pepper notes and 8 percent alcohol by volume (ABV). More visible, though hardly best-sellers, are the strong beers from Náchod's Primátor Brewery, of which the 24° "Double" clocks in at a winelike 10 percent ABV. For years it has been recognized as the strongest beer in the country.

But that status changed with the arrival of Prague's newest microbrewery, located inside the storied U Medvídků pub. While U Medvídků's downstairs beer hall still serves its standard draft Budvar, the newly constructed brew-pub upstairs makes — or made — the new strongest beer in the country: X-30, brewed at a remarkable 30° Balling and knocking out an incredible 11.8 percent ABV. Produced in a limited edition and only available in bottles, it quickly sold out after the brewery's opening in mid-2005.

But fortunately, Micropivovar U Medvídků still has plenty of its delicious standard lager, a half-dark 13° beer named Oldgott. With just 5.2 percent ABV, Oldgott is clear dark amber in color with a thick-set, light tan head, perfectly incorporated alcohol, a rich malt body and dry, bittersweet finish. It is made with three kinds of malt — caramel, Bavarian and Pilsner — and 100 percent Czech hops from Žatec (aka Saaz). Lagered in traditional wooden barrels for at least six weeks, the beer's rustic production fits perfectly with the location, a beloved Old Town destination with a history dating back to 1466.

But passionate beer hunters needn't feel disappointed that they missed out on the X-30. Currently in production is the brewery's follow-up, the X-33, made at 33° Balling and expected to arrive at 12.5 percent to 13 percent ABV. It will take seven months of lagering and more than a little magic to get the beer to produce that much alcohol, according to brewer Ladislav Veselý.

"Our normal yeast stops at around 8 or 10 percent alcohol," Veselý says. "So we need two types in the 33."

The first type is the traditional saccharomyces carlsbergensis, a classic Pilsner-type yeast that Veselý says he gets from Pivovarský dům. But don't expect him to tell you much else.

"The first is carlsbergensis," he says with a laugh. "The second is a big secret."