In the previous article, we clarified that the heart of sake brewing lies in parallel multiple fermentation.
Kōji makes sugar, and yeast makes alcohol. This simultaneous process is the core of how sake is made.
So how do brewers keep this parallel process stable?
This is where dan-jikomi (stepwise addition) comes in.
Sake is not made by adding all ingredients at once and letting them ferment.
Instead, the mash is built up in stages: Hatsuzoe, Odori, Nakazoe, and Tomezoe.
Why go through the trouble of splitting the additions?
Once you understand the reason, you can see that sake brewing is not just “tradition” or “rules of thumb” — it is a carefully designed process.
What Is Dan-Jikomi?
Dan-jikomi is a method of adding kōji, steamed rice, and water to the yeast starter (shubo) in three separate additions.
- Hatsuzoe (first addition): Add a small amount to let the yeast adjust.
- Odori (“rest day”): Wait one day to let the yeast multiply.
- Nakazoe (second addition): Increase the volume significantly.
- Tomezoe (final addition): Complete the mash at the final volume.
Because the ingredients are added in three main stages, this method is also called sandanjikomi (three-stage addition).
Why Not Add Everything at Once?
If you add a large amount of rice and water from the beginning, the yeast population may be too small relative to the total volume, and fermentation can become unstable.
Dan-jikomi allows the mash volume to grow while keeping yeast in a dominant position.
Why “Three” Stages?
Most people know that dan-jikomi uses three main additions — but let’s think one step deeper.
Why not two stages, or four?
The key is the balance between yeast growth speed and how fast the mash volume increases.
The yeast cultivated in the starter faces a major environmental shift during Hatsuzoe.
The water volume increases, sugar concentration changes, and temperature conditions can shift as well.
If too much rice and water are added at once, yeast may not adapt fast enough, and its growth may not keep up.
That gap can create an opportunity for unwanted microbes.
So brewers first add a small amount in Hatsuzoe to let yeast adjust.
Then they use Odori to let yeast multiply sufficiently.
After that, they expand the mash step by step with Nakazoe and Tomezoe.
In other words, three stages are a practical and rational design that allows the mash volume to expand safely while yeast continues to grow.
With two stages, there may not be enough time for growth and stabilization. With four or more, the process becomes too complex.
Through accumulated experience, “three” became the most reliable form.
So sandanjikomi is easier to understand not as “tradition,” but as a design aligned with microbial growth speed.
So how does yeast actually grow during this process?
Going Deeper: Yeast Growth and Sandanjikomi
To understand sandanjikomi more deeply, focus on how yeast multiplies.
Yeast does not increase immediately when the environment changes.
First, there is an adaptation phase. Then yeast enters a rapid growth phase.
If you add a large amount of rice and water from the start, yeast may still be adapting and may not multiply enough before fermentation moves forward.
With sandanjikomi, the flow is:
- Change the environment with Hatsuzoe
- Increase yeast during Odori
- Expand rapidly with Nakazoe and Tomezoe
This timing matches the yeast growth curve and keeps fermentation stable.
In exams, questions may ask about “the purpose of Odori” or “the significance of sandanjikomi.”
If you remember the core idea — increase the volume only after yeast has multiplied sufficiently — you’ll be less likely to get confused by similar-looking answer choices.
Odori Is Not “Doing Nothing”
Odori is a one-day pause after Hatsuzoe.
But it is not an inactive period.
During Odori, yeast multiplies rapidly and produces alcohol and acids.
As alcohol rises and pH drops, the environment becomes hostile to unwanted bacteria.
Odori is the time for yeast to “take control” of the mash.
How It Supports Parallel Multiple Fermentation
Dan-jikomi is not just a traditional technique.
It is a control method that stabilizes parallel multiple fermentation.
Kōji keeps supplying sugar, and yeast keeps producing alcohol.
If that balance breaks, fermentation becomes unstable.
Dan-jikomi maintains balance by adjusting sugar supply and yeast growth step by step, rather than changing everything at once.
Summary
Dan-jikomi acts like a safety mechanism in sake brewing.
- Keep yeast dominant
- Reduce contamination risk
- Stabilize fermentation
Sandanjikomi is designed to make parallel multiple fermentation succeed.
When you understand each step as “why this order,” the logic of sake brewing becomes much clearer.
▶ Next: Learn About Hiire (Pasteurization)
With sandanjikomi, fermentation proceeds in a stable way and the basic structure of sake is formed.
So when do brewers stop fermentation, and how do they stabilize quality?
What Is Hiire? — Easy Guide to Namazake, Namachozo, and Namazume
In the next article, we整理 the key process of hiire and clarify how it differs from unpasteurized sake.
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