How is sake made? The magic behind water, rice, and koji
Split
Table of contents
- The 4 sacred ingredients
- Koji: The fungus that makes everything possible
- The process: Why sake is more difficult than wine
- The Toji: A Life for Sake
When you hold a bottle of premium sake in your hand that costs 30, 50 or 100 euros, you might ask yourself: "Why is this more expensive than my Riesling?"
The answer lies in the effort involved. Brewing sake is a physical and chemical high-wire act. While nature does most of the work with wine (grapes have sugar, yeast consumes sugar = alcohol), the sake brewer has to produce the sugar himself. In the middle of winter. By hand.
The 4 sacred ingredients
According to the Japanese purity law, only four things are needed for premium sake (Junmai):
- Saka-Mai Rice: Special sake rice that is larger and stronger than table rice. It is polished to remove fats and proteins.
- Water: Sake is 80% water. Japanese water is almost always extremely soft, which gives sake its silky texture.
- Yeast (Kobo): It determines the aroma – from banana to apple.
- Koji: The Secret.
Koji: The fungus that makes everything possible
There is an old saying among brewers: "First koji, second moto (yeast starter), third moromi (mash)."
Koji is steamed rice that has been dusted with a fine mold ( Aspergillus oryzae ). This mold has only one job: it breaks down the starch in the rice grain and converts it into sugar.
The craft: Koji is produced in a special, sauna-like room (muro). The brewmaster must check the temperature every few hours over a 48-hour period and manually stir the rice – often in the middle of the night. One mistake here, and the entire batch is ruined.
The process: Why sake is more difficult than wine
Sake uses a technique that is unique worldwide: multiple parallel fermentation .
The difference explained simply:
- Beer: First starch to sugar (mashing), THEN sugar to alcohol (fermentation). One after the other.
- Sake: The koji converts starch into sugar, while SIMULTANEOUSLY in the same tank, the yeast converts the sugar into alcohol. Everything happens in parallel.
This is biochemical chaos that must be perfectly controlled. To avoid overwhelming the yeast, the ingredients (water, rice, koji) are not added to the tank all at once, but in three stages over four days ( Sandan Shikomi ).
The Toji: A Life for Sake
The head of the brewery is called a Toji (brewmaster). Traditionally, Tojis leave their families in the autumn and live at the brewery throughout the winter without a single day off. They often sleep only a few hours to monitor the delicate koji.
So the next time you sip a Daiginjo , you're not just tasting rice and water. You're tasting the sleepless nights and devotion of the Toji.
Would you like to taste this craftsmanship?
We have curated sakes from small, artisanal breweries (jizake) that still live these traditions today.
