During malting the barley grains elaborate carbohydrases, which act primarily on starch, and proteolytic enzymes that break down proteins. The proteolytic enzymes include proteases which hydrolyze long-chain proteins to smaller ones, and peptidases which break down proteins to amino acids. The quantity and type of proteins in malts have profound effects on the quality of malts and beer. The right combination of amino acids and medium-sized proteins is needed for the efficient production of high-quality beer. The amino acids are used for the nourishment of yeasts to ensure vigorous fermentation and the medium-sized proteins are crucial for foam retention in the final product. Malts with low proteolytic activity contain large amounts of long-chain proteins that slow down the wort filtration and create hazes in the final beer. Malts with excessive proteolytic activity contain high quantities of amino acids that cause excessive darkening during boiling of the wort and produce beer with low foam potential and a weak body.

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Protein significantly influences malt processing and beer quality, as demonstrated in various scientific studies. Research has shown that protein content affects malt modification, including the regulation of enzymes such as proteases during malting. Additionally, studies have demonstrated the impact of proteins on wort viscosity, foam stability, and yeast nutrition during the brewing process. Furthermore, scientific evidence supports the role of proteins in haze formation and colloidal stability in beer. These findings underscore the significance of protein in malt processing and its far-reaching implications for beer production.