Bavaria is the home and heart of dunkel brewing. Hundreds of breweries pock the landscape in Bavaria from Munich in the south to Franconia in the north. Franconia alone has over 400, many of which are very small. A good percentage make dunkel, some of which is very refined, some unfiltered. Some are deep amber, while others have a rugged, lightly roasted character and an almost black appearance. Most are a rich reddish-brown, all are unmistakably Bavarian.
Dunkels are remarkable beers in that they are deep and complex, but not very heavy or strong. The characteristic ruby brown color comes from the use of Munich malts, which can actually constitute up to 100 percent of the grist. The gentle kilning of pale malt not only darkens the kernels, but also catalyzes a cascade of biochemical changes in the malt that contribute a range of subtle, malty flavors. Munich malt is less fermentable than a lighter malt such as pilsner malt. This results in a fuller-bodied, dextrinous beer. Special malt indeed.
Brewers of dunkel often employ a method of mashing known as decoction. Rather than simply infusing the grains with hot water, decoction brewing involves heating portions of the mash to boiling, and returning it to the main mash to attain the necessary temperature points to convert the starches into fermentable maltose and body-building dextrin. Heating the mash to boiling induces further chemical alterations, known as Malliard reactions, that give the brew its intense, malty character, and further darken the wort.
While the balancing act that is dunkel tips towards the malt character, the hops are subdued but noticeable in the aroma and provide just enough bitterness to keep the brew from being sweet. Of course, the hops are the noble varieties from the Tetnang and Hallertau regions; these augment dunkel’s unmistakable German character.
The cool fermentation and extensive lagering times typical of bottom-fermenting beers are naturally employed in dunkel production. This patient approach to beer maturation provides a smooth platform with which to showcase the prominent malt and supporting hop character of dunkel.
A typical dunkel begins with an original gravity in the range of 1.048 to 1.053, or perhaps a couple points on either side of this spread, giving it an alcohol by volume content of about 4.5 to 5.6 percent.