In last week’s column, I discussed Oktoberfest beers. But the country that is nearly synonymous with great beer has many styles to explore. Among these are several heavier German varieties that, as the temperatures moderate, provide a bit of alcohol-induced inner warmth for hearty drinkers in the biergarten.

First brewed by Paulaner friars of the Franciscan order who moved to Munich from Italy in 1627, doppelbocks are dark lagers ranging in color from dark gold to dark brown, with an alcohol content of seven- to 12-percent by volume. The style’s name literally means “double bock.” They were originally brewed to provide sustenance to monks during fasts such as Advent and Lent. The heavy nature of the brew made it a perfect “liquid bread,” and the higher alcohol uplifted their spirits, so much so that some questioned whether substituting the beer for food was truly suffering as required by religious rule.

To determine if subsisting on doppelbock was a suitable means of penance, a cask was sent to the Holy Father. The road to Rome took the cask along bumpy, poorly maintained routes through the towering Alps. By the time it reached Vatican City, the brew had endured temperature extremes and constant jostling. Thus, when the Pope tried it, the flavor had seriously deteriorated. He deemed it the worst beer he’d ever tasted and thus suitable to maintain suffering while fasting.

Most doppelbocks have a hint of chocolate and dark fruits, like raisins and plums, in an aroma that rises from a thick, creamy head. The flavor is usually intensely malty and sweet with little or no hops. Dedicated to Christ, the friars from St. Francis of Paola named the beer “Salvator,” meaning “savior.” A tradition carried on by today’s brewers of the style often end their brew’s name with “-ator.”

Doppelbock is not the pinnacle of high-alcohol bock beers, though. That crown rests squarely on the creamy head of eisbocks. With colors ranging from deep copper to dark brown and alcohol content beginning at nine percent, “ice beer” is the ABV ruler.

The origin of eisbock is unclear; legend has it that a lazy cellarman left a cask of strong bockbier outside on a very cold night. When he returned the next morning, the cask’s lid had burst upward and a solid block of ice covered the liquid. When the brewmaster moved the ice, the beer underneath was more concentrated, sweeter and considerably more alcoholic. In his dereliction of duties, the cellarman had accidently created a new style.

Traditional versions of this very strong style feature intense aromas of dark fruits and sweet, toasty malts. The rich flavor is sweet with notes of chocolate and significant alcohol. Most versions range from nine- to 13-percent ABV, but the strongest, Koelschip Mistery of Beer, was brewed by the now-defunct Brouwerij’t Koelschip. At 70 percent ABV, it was not a casual quaff.

So to keep your German beer exploration going during this Oktoberfest season, seek dopplebocks and eisbocks. And plan on staying in for the night–these brews pack one hell of a punch.