Hakumai buai (white rice ratio in the moromi)

Hakumai buai is an indicator of the proportion of white rice in the moromi (fermentation mash) in sake brewing. The value is measured immediately after the final addition of the mash (tome-jikomi), and it is therefore also called "tome sokuji buai" (留即時歩合). It is calculated as follows: hakumai buai (%) = ((liters of moromi immediately after the final addition − liters of brewing water) ÷ kg of white rice) × 100. In general, hakumai buai becomes higher when the water absorption of the steamed rice and koji is high. This indicator is an important factor affecting the character and flavor of sake.