Making beer is a somewhat complex process. One mostly commercial method begins by mixing and mashing malted barley with a cooked cereal grain such as corn. This mixture, called “wort,” is filtered before hops are added to it. The wort is then heated until it is completely soluble. The hops are removed, and after the mixture has cooled, yeast is added. The beer ferments for eight to eleven days at temperatures that range from 50 to 70°F (10–21°C). The beer is then stored and kept at a state that is close to freezing. During the next few months, the liquid takes on its final character before carbon dioxide is added for effervescence. The beer is then refrigerated, filtered, and pasteurized in preparation for bottling or canning.