Several years ago, the brewers began working with a unique Bavarian hefeweizen yeast strain unknown in this country. This amazingly flavorful yeast was so exciting that they began working on a recipe for a traditional German hefeweizen with the Sierra Nevada twist. Traditional hefeweizen is a style that seems deceptively simple, but in reality is devilishly complex. For years the brewers weren’t satisfied with the beer; something was missing. In a flash of inspiration, an epic trip was arranged. The brewers took a whirlwind tour through the legendary Bavarian wheat breweries to see what they were doing. It was there they realized the advantages of making wheat beer using the traditional system of open fermentation.
Sierra Nevada had been making a portion of their beer using the difficult and labor-intensive technique of open fermentation for years. Most modern brewery fermentation takes place in closed, stainless-steel tanks; this method is efficient, quick and clean. In closed tanks, however, the yeast doesn’t have the opportunity to coax as much complexity from the fermenting beer. Using shallow open fermentation, the yeast has space to build layers of flavors and aroma that would otherwise be impossible.
After seeing the technique in use in Germany, the inspiration to make Kellerweis in the open system took hold. The name is an homage to the German Keller, meaning cellar—the name breweries give to their fermentation systems, and weis, or weiss—the German name for “white” or wheat beer, hazy with suspended yeast.
Kellerweis is a light and refreshing beer with deep complexity of flavor. The yeast provides hints of fruit flavors and spices, including ripe banana and clove. This hazy-golden beer glows with suspended yeast creating a velvety texture; perfect for a sunny California day. Sierra Nevada’s Kellerweis Hefeweizen will be available in 6-packs and on draft starting in late spring 2009.