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Sake as Brewed alcoholic beverages

Brewed alcoholic beverages is made by fermenting sugars with the help of yeast (converting sugars to alcohol and carbon dioxide, etc.). The brewing depends on what kind of ingredients are used and is categorized into three main types of processing;
First, a simple fermentation. Wine originated from a fruit having sugars by itself and is fermented by its own glucose and yeast. This is called a simple fermentation.
Second, a multiple sequential fermentation. For making beer, malt is used. It has diastatic enzyme/maltase, which converts wheat starch into maltose, and then ferments the maltose by yeast. This two-step-fermentation is called a multiple sequential fermentation.
Then, how about Nihonshu? It is made of rice, containing no sugars and no diastatic enzyme. This means it requires a process to create sugars and diastatic enzyme.
So there comes the third fermentation, a multi-parallel fermentation. Using white rice and koji mold, rice koji is created containing diastatic enzyme/amylase. This rice koji converts rice starch into glucose, and then, with the help of yeast, ferments the glucose. These two steps are concurrently done in one tank, so it is called a multi-parallel fermentation.