is the portion of the malt solids that are soluble in cold water expressed as a percentage of the weight of the malt. The test is carried out at 20°C (68°F) using water with ammonia added to inhibit any enzyme action. It serves as a measure of the degree to which the malt has been modified in the malt house. Figures in the 15%–22% range are considered acceptable. The cold water extract consists of simple sugars, amino acids, and other soluble components produced during the breakdown of the endosperm of barley during malting. See endosperm. Maltsters producing specialty malts in a roasting drum will deliberately allow the enzymic breakdown of the barley endosperm to continue to near completion, creating very high cold water extract prior to roasting. This provides large amounts of simple carbohydrates and amino acids for the desirable Maillard reactions that occur during roasting. See maillard reaction. Brewers are less likely to worry about the cold water extract as a parameter of their malt directly, but do use the number as an inference of other characteristics of the malt, such as the degree of modification. They will also track the variation in the number as a measurement of malting consistency.
See also malting, modification, and roasted malts.
