Grain product used in beverages and foods. Malt provides a basis for fermentation and adds flavour and nutrients. It is made by steeping grain, usually barley, in water and allowing partial germination to occur. The flavour of beer primarily results from the malt from which it is made. The enzymes produced within the barley seed during germination break down starch into malt sugar, or maltose, which is then fermented by yeast to yield alcohol and carbon dioxide. Whiskey likewise is made with malt.
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Malting is a process applied to cereal grains, in which the grains are made to germinate by soaking in water and are then quickly halted from germinating further by drying/heating with hot air. Malting is thus a combination of two processes; namely the sprouting process and the kiln-drying process. These latter terms are often preferred when referring to the field of brewing for batches of beer or other beverages as they provide more in-depth information.
The term "malt" refers to several products of the process:
Whisky or beer can also be called malt, as in Alfred Edward Housman's aphorism "malt does more than Milton can, to justify God's ways to Man."
Malted grain is used to make beer, whisky, malted shakes, and malt vinegar. Malting grains develops the enzymes that are required to modify the grain's starches into sugars, including monosaccharides (glucose, fructose, etc.) and disaccharides (sucrose, etc.). It also develops other enzymes, such as proteases which break down the proteins in the grain into forms which can be utilized by yeast. Barley is the most commonly malted grain in part because of its high diastatic power or enzyme content. Also very important is the retention of the grain's husk even after threshing, unlike the bare seeds of threshed wheat or rye. This protects the growing acrospire (developing plant embryo) from damage during malting, which can easily lead to mold growth. It also allows the mash of converted grain to create a filter bed during sparging (see brewing). Other grains may be malted, although the resulting malt may not have sufficient enzymatic content to convert its own starch content fully and efficiently and may create a "stuck sparge" .