Malt sandwich is germinated cereal grain that has been dried in a process known as “malting”. The grain is made to germinate by soaking in water and is then halted from germinating further by drying with hot air. Various cereals are malted, though barley is the most common.

A high-protein form of malted barley is often a label-listed ingredient in blended flours typically used in the manufacture of yeast bread and other baked goods. A plate or bowl of samanu is a traditional component of the Haft sin table symbolising affluence. Mämmi, or Easter Porridge, is a traditional Finnish Lenten food. Today, this product is available in shops from February until Easter.

Barley is spread out on the floor of a malthouse during a traditional malting process. Malting is the process of converting barley or other cereal grains into malt for use in brewing, distilling, or foods, and takes place in a maltings, sometimes called a malthouse, or a malting floor. As of 2014, the largest malting operation in the world was Malteurop, which operates in 14 countries. Barley is the most commonly malted grain, in part because of its high content of enzymes, though wheat, rye, oats, rice, and corn are also used. As all grains sprout, natural enzymes within the grain break down the starch of which the grain is composed into simpler sugars, which taste sweet and are easier for yeast to use as food. Malt with active enzymes is called “diastatic malt”.

Malt with inactive enzymes is called “nondiastatic malt”. The enzymes are deactivated by heating the malt. Malt is often divided into two categories by brewers: base malts and specialty malts. Base malts have enough diastatic power to convert their own starch and usually, that of some amount of starch from unmalted grain, called adjuncts. Specialty caramel or crystal malts have been subjected to heat treatment to convert their starches to sugars nonenzymatically. In addition, malts are distinguished by the two major cultivar types of barley used for malting, two-row, and six-row. Malt extract, also known as extract of malt, is a sweet, treacle-like substance used as a dietary supplement.

The 1907 British Pharmaceutical Codex’s instructions for making a nutritional extract of malt do not include a mashout at the end of extraction and include the use of lower mash temperatures than is typical with modern beer-brewing practices. 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 it to halt the progress when the sprouting begins. The drying step stops the sprouting, but the enzymes remain active due to the low temperatures used in base malt production. In the next step, brewers use a process called mashing to extract the sugars. Brewers warm cracked malt in temperature-modulated water, activating the enzymes, which cleave more of the malt’s remaining starch into various sugars, the largest percentage of which is maltose.