Homebrewing beer. In this episode of Brew Strong, our heroes take a show suggestion from a listener and delve into the origins and control of esters in beer. Esters are a metabolic byproduct that are formed by the yeast during growth when they need to eliminate excess waste created from the synthesis of long chain fatty acids, sterols and other lipids. If they are grown under stressful conditions, they will produce more. The factors for controlling ester production during fermentation are discussed. Learn more about your ad choices. Visit megaphone.fm/adchoices