Provided are methods of making and using an antimicrobial composition, optionally including adding one or more enzymes to a suspension of lees, wherein the lees was formed by fermenting fruit with yeast and the one or more optional enzymes comprise a protease, a carbohydrase, or a combination of a protease and a carbohydrase; and forming a dried lees by drying the lees. In some examples the fruit includes chardonnay grapes, pinot noir grapes, cabernet franc grapes, or a combination of any two or more of chardonnay grapes, pinot noir grapes, and cabernet franc grapes; the yeast includes one or more Saccharomyces cerevisiae strains of yeast; and drying the lees by heating it. In some examples, trub made from fermenting a grain such as barley is used instead of lees. An antimicrobial composition made as provided may be administered to an animal to inhibit bacterial growth.