Mashing is the process of mixing and infusing crushed malts, unmalted grains, and adjuncts with hot water from the hot liquor tank. As the grains and adjuncts mix with the hot water at specific temperatures, enzymes from the malt activate and convert the starches into sugars. At the same time that the starches are being converted to sugars, color is also being extracted from the grains, which is the primary determining factor of the beer’s final color. The mashing process takes place in a brewing vessel called a mash tun.
Below is a photo of crushed grain being stirred in the mash tun during the mashing process.
The mash is water-saturated crushed malts, unmalted grains, and adjuncts that are present in the mash tun when the mashing occurs. During the mashing process, the starches will be broken down into sugars so they can be fermented by the yeast and converted into alcohol.
The mash for an American Wheat Hefeweizen towards the end of the mashing.
A mash bill or grain bill is the whole of the different malts, grains, and adjuncts that make up a beer. The mash bill is very important when designing a beer recipe, as it is primarily responsible for the potential original gravity, color, and diastatic power of the beer.