Although sake is also deﬁned as a brewed alcoholic beverage, the brewing process is more complex than that employed for beer and wine.
In the wine production process, the crushed grapes ferment naturally after yeast is added. In the case of beer, similarly, fermentation takes place after yeast and hot water are added to crushed malt. But the rice used to make sake does not begin to ferment with the addition of yeast alone.
Sake brewing begins with the introduction of koji, which break down rice starch into glucose in a process known as “sacchariﬁcation.” Next, sake yeast is added and fermentation begins. This process, in which sacchariﬁcation and fermentation take place in the same vat at the same time, is called “multiple parallel fermentation.”
This is a unique feature of sake brewing that distinguishes it from every other brewing process.
Koji are microbes, similar to these used in blue cheese production, that are good for the health. Shouyu(soy sauce) and miso(soy bean paste) are also produced using similar beneﬁcial microbes.
Along fermentation process -which can be as much as three to four times that of wine- produces a wide variety of amino acids, giving sake a balanced, rounded taste and fresh flavour.
Yes, controlling the complex sake-brewing process requires intuition as well as knowledge of special techniques. For this reason, every sake maker has its own brewery master known as a toji. The toji manages not only the sake-brewing process but also the activities of his brewing team, including their work shifts and living arrangements. Maintaining a good team spirit is essential to sake brewing.
The toji lives at the work site as long as he is in control of the brewing process. When he grows old, he appoints a hand-picked successor, to whom he has passed down his brewing know-how and techniques.