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.