Three-Stage Addition Process

## Building the Mash Safely

{{glossary:sandan-jikomi}} (three-stage addition) is the method by which the main {{glossary:moromi}} mash is assembled over four days. This careful, stepwise approach ensures that the yeast population remains strong enough to protect against contamination at each stage.

## Day 1: Hatsuzoe (First Addition)

On day one, steamed rice, {{glossary:koji}}, and water are added to the {{glossary:moto}} (yeast starter), roughly doubling its volume. This first addition dilutes the moto's protective acidity, so the amount is carefully calibrated to keep the yeast-to-bacteria ratio favorable. The mixture is stirred and the temperature is managed.

## Day 2: Odori (Dancing Day)

Day two is a deliberate rest day. No ingredients are added. The yeast population uses this time to multiply and fill the expanded volume. The name "odori" (dancing) comes from the vigorous bubbling visible as yeast actively ferments. This pause is critical — without it, the next dilution could overwhelm the yeast.

## Day 3: Nakazoe (Middle Addition)

On day three, a second and larger batch of steamed rice, koji, and water is added, again roughly doubling the mash volume. The yeast, now fortified from the rest day, can handle this dilution. The moromi begins to develop its characteristic aroma.

## Day 4: Tomezoe (Final Addition)

The final and largest addition brings the moromi to its full volume. After tomezoe, the mash is complete, and the 18-32 day fermentation period begins in earnest. The toji monitors temperature, gravity, and acidity daily from this point forward.

## Why Not Add Everything at Once

If all ingredients were combined simultaneously, the yeast concentration would be too low to suppress wild bacteria. The high-sugar, low-acid environment would be an open invitation for contamination. The three-stage approach, developed empirically centuries ago and validated by modern microbiology, elegantly solves this problem.