Malt extract production [edit]. Malt extract is frequently used in the brewing of beer. Its production begins by germinating barley grain in a process known as malting, immersing barley in water to encourage the grain to sprout, then drying the barley to halt the progress when the sprouting begins.alting is the process of converting barley or other cereal grains into malt, for use in brewing, distilling, or in foods and takes place in a maltings, sometimes called a malthouse, or a malting floor.