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 color or colour of a beer is typically described using either the Standard Reference Method scale (SRM), Lovibond scale, or European Brewery Convention (EBC) scale, which reference a numerical value to define the color and shade, and in some cases clarity or turbidity of a beer. The higher the number, the darker the referenced color is.
A beer’s color is primarily composed from the pigments of the grains that make up its grain bill. The pigment of a grain will darken if it is toasted, caramelized, or roasted, and that will impart that color on the finished beer. In the case of an imperial stout, the roast of the malt is so dark that it makes the beer nearly black. It is important to remember that as the color of the grain darkens, the acidity typically increases. Beer can also gain color from adjuncts, such as fruits and sugars.
Though not as common in all styles of beer, blending is very important when making beers such as sours or when brewing on the macro level. Blending allows you to achieve your desired flavor or color profile by blending two or more batches of beer together. In some cases, beers of dramatically different ages will be mixed together, like in the case of Rodenbach Grand Cru, where their young ale is mixed with their wood vat two year old ale to create a fuller taste.