Starch is useful in giving beer its body, but sugars supply the alcohol content and carbonation. The malted grains are added to a tank called a mash-tun with warm water to break the starches down into sugars. Brewers take advantage of the grains’ own enzymes, called amylases, to break the starch down into sugars that yeast can digest. Other enzymes, called proteases, break down the grains’ proteins into more bite size pieces for the yeast. Warm water and very specific acid contents (pH’s) allow proteases and amylases to work their best.