is unmalted, cooked, and dried barley that has been rolled into flat flakes. It imparts a rich, grainy flavor to beer and is used in many stouts, particularly Irish stouts, enhancing head formation and foam stability. Flaked barley, which is used directly in the mash mixer along with malt, belongs to a group of pre-cooked gelatinized adjuncts that includes micronized and torrefied whole grains and comprises flaked barley, wheat, flaked maize grits, flaked rice grits, and flaked pearl barley. See adjuncts. These materials are easily handled and yield enhanced extracts compared to untreated raw materials. Because it has been soaked and pre-cooked, flaked barley is relatively soft and is easily broken up in malt mills. To produce flaked barley, whole barley (graded to remove thin grains) is cooked in hot air at 428°F–500°F (220°C–260°C). During cooking the softened material becomes firm with a moisture content of approximately 4%. Flaked barley has an extract value of 72% on a dry weight basis.

Flaked barley and, to an even greater extent, flaked pearl barley (grains from which the husk and surface layers have been removed) can present brewing problems because they contain comparatively large amounts of β-glucan. See beta-glucans. In order to overcome this problem, flaked barley is often sprayed during preparation with a solution of bacterial enzymes containing α-amylase, β-glucanase, and possibly proteinase. The resulting product has an appreciable cold water extract and does not give rise to highly viscous worts or any other problems associated with β-glucans.