The Relevance of Different Enzymes for the Hydrolysis of β‐glucans in Malting and Mashing

β‐Glucosidase and to a lesser extent endo‐β1–4‐glucanase are present in significant quantity in raw barley. These enzymes, as well as endo‐β1–3, 1–4‐glucanase, endo‐β1–3‐glucanase and exo‐β1–3‐glucanase, increase in activity during steeping and germination. Exo‐β1–3‐glucanase stands apart through its very late development during germination and it may be a limiting enzyme in malts that have not received substantial modification. Three separate exo‐glucanases were located in malt and each of them displayed a preference for β1–3 linkages. As the principle product of endo‐β1–3, 1–4‐glucanase is oligosaccharides with a β1–4 linkage at the non‐reducing end (from which end exo enzymes approach the substrate), this is likely to be a second reason (alongside the late development of the enzyme) why such oligosaccharides survive in significant quantities into wort. A third contributing factor may be the sensitivity of the exo‐glucanases to ions such as potassium, sodium and magnesium.