a porridge-like mixture of ground cereal grains (grist) and temperature-controlled brewing water (often called “liquor”). Mashing, the act of producing a mash, is the first stage in brewing beers of any style in any brewery, its purpose being to convert starch and protein in the grist into sugars and amino acids that are assimilable by yeast. See mashing. The cereals that make up the mash, the chemical composition, and the volume and temperature of the brewing water are integral determinants of a beer’s recipe, final taste, and character. A mash is traditionally made in a mash tun in ale breweries in the UK. It normally contains only malted barley—several types of malt may be used—but sometimes has a small percentage (maximum of 15%) of other cereals such as wheat. The mash in a mash tun is fairly thick compared with mashes used in lager brewing, which are thinner because they take place in a mash mixing or conversion vessel. See infusion mash. A lager mash often goes through a series of temperature rises during which enzymes in the malt differing in their tolerance to heat act successively to produce the liquid sugar extract called wort. See wort. In traditional ale mashing the wort is run from the grains in the mash tun. Lager mashes are transferred to a mash separation device such as a lauter tun or mash filter in which the wort can be washed out of the mash by spraying with brewing water (sparging).
