Shikkatsu (enzyme inactivation)

Inactivation (shikkatsu) refers to the loss of function in enzymes or enzyme proteins when their structure changes under the influence of heat, chemical substances, or similar factors. In sake production in particular, when inactivation occurs, the activity of the enzymes needed for fermentation declines, which can seriously affect the brewing process. For example, inactivation of saccharifying enzymes can hinder the conversion of rice starch into sugar, and fermentation may stall. For this reason, appropriate temperature control and careful handling of enzymes are extremely important.