Maximum velocity (Vmax)
Japanese: Vmax（最大反応速度）
The maximum speed an enzymatic reaction can achieve—the velocity when all enzyme molecules are saturated with substrate.
Vmax is the reaction velocity when all enzyme molecules are bound to substrate—a saturated state. Adding more substrate beyond this point does not increase speed.
Vmax is proportional to enzyme concentration. Doubling koji theoretically doubles Vmax. This means koji ratio (the proportion of koji used) is indirectly designing Vmax.
The combination of Km and Vmax draws the 'character' of an enzyme. An enzyme with small Km and large Vmax is a 'high-performance engine' that works furiously even with little substrate. In selecting koji mold strains for brewing, such enzymatic characteristics are crucial selection criteria. It is an indispensable metric for evaluating enzyme performance. Deep expertise supports both the inheritance and innovation of fermentation culture.