Malt & Grain

Barley becomes malt when it's soaked, allowed to germinate, and then dried in a stream of hot air. This drying process is called kilning. It halts germination and sets the color: the hotter and longer the kilning, the darker and more roasted the malt tastes. Pale malt is kilned gently at low temperatures, while malt for darker beers is kilned at significantly higher heat.

Color is measured in EBC units. According to BJCP style guidelines, a Festbier falls between 8 and 12 EBC, making it golden yellow. A Märzen ranges from 16 to 33 EBC, spanning deep gold to copper-brown.

How robust a beer turns out depends on the amount of malt in the brew. The original gravity—the proportion of dissolved solids in the wort before fermentation—runs from 13.3 to 14 degrees Plato for a Festbier. The yeast later converts this sugar into alcohol, which is why it lands at 5.8 to 6.3 percent ABV. Auerbräu's Rosenheimer Herbstfest-Märzen comes in at 5.6% ABV, at the lower end of the Märzen range.

In Bavaria, all the sugar comes from malt. Added sugar has been banned here since 1924, even for wheat beer. Both Rosenheim breweries carry a wheat beer, made with wheat malt, which gives it its soft, almost creamy fullness.

On the palate, the malt comes through as bread crust, honey, and a light caramel note, with the darker Märzen beers also showing a gentle roasted edge. The beer rarely tastes sweet, though, because the yeast has fermented out nearly all the sugar. A Festbier relies on pale malt with little roasted character, while a Märzen can carry more color malt.