Malting is a process applied to cereal grains, and the term malt can refer to several products of the process:

  • grains to which this process has been applied, e.g. malted barley
  • sugar derived from such grains and heavy in maltose, e.g. baker's malt
  • a product using such sugar (e.g., malted milkshakes), which imparts a distinctive flavor.

Malting grains is necessary to develop enzymes which are required to modify the grain's starches into sugars. Barley is the most common malt due to its high enzyme content. Other grains may be malted, although the resulting malt may not have sufficient enzymatic content to fully and efficiently convert its own starch content.

The typical "pale malt" malting process is as follows:

  • fresh raw grains are washed and soaked for a period of time to begin germination
  • a constant moisture is held to promote germination and growth of the acrospire
  • the acrospire is allowed to grow to a length equal to the grain, or a little less (about 4-6 days for barley)
  • this "green malt" is then kilned at 100 °F to 120 °F (38 °C to 49 °C) for about 24 hours and then at 140 °F to 160 °F (60 °C to 71 °C) until the moisture content is less than 6%

Darker brewing malts are sometimes kilned in different ways to promote different characteristics.

Malt is used to make beer, whisky, malt vinegar.

Source: William Starr Moake. (August, 1997) Make your own malt. Brew Your Own: The How-To Homebrew Beer Magazine (ISSN 1081-826X), pages 32-36, volume 3, number 8.