The actual temperature of the a-amylase is 72-75°C, while the β-amylase is 62-65°C. This is the temperature commonly used in beer production.
(1) At a temperature of 72-75°C, a-amylase decomposes long-chain starch into low-molecular-weight dextrins, which has the best effect. The a-amylase inactivation temperature is 80°C and the optimum pH is 5.6-5.8.
(2) At the temperature of 62-65°C, β-amylase decomposes from the ends of the starch chain to form maltose, maltotriose, and glucose, and has the best effect. The deactivation temperature is 70°C and the optimum pH is 5.4-5.5.