July 11, 2014 by Prost Brewing
Do you taste banana or bubblegum flavors when you take a sip of Prost’s Weißbier? How about some subtle sweetness resembling apple or pear when drinking a Kölsch? The esters in these biers are part of what you’re tasting, and they’re produced during fermentation. Esters are flavor compounds left behind after yeast ferments the wort and converts sugars into alcohol and carbon dioxide. They contribute sweet, fruity and solventy aromas, among others. Esters are usually expressed in chemical terms as ethyl acetate.
While we don’t want higher ester levels in any of our biers, all of our styles differ in what is an acceptable level of esters. Many pleasant estery flavors are enjoyable and desired in top-fermented biers and dark biers, adding complexity and intrigue that’s appropriate for the style. For many bottom-fermented biers, little to no ester presence should be detected. This is due to the type of yeast used for fermentation, and the longer time period for lagering. Biers like our Pils and Märzen Oktoberfest have a clean finish with no trace of esters.
Each step of the brewing process is so crucial to a perfect finished product, and fermentation is no exception. Knowing the science behind what our biers are made of and how they should taste as a result of the process is the essence of brewing. We’re privileged to use this science to bring you the finest German style bier in the Rocky Mountain region. Prost!