Sake Basics

Sake is a unique and delicious alcoholic beverage fermented from rice, and is known in its native Japan as nihonshu, which means Japan's alcohol.

It *isn't* distilled.

It *isn't* rice "wine."

In fact, nihonshu isn't like any other fermented beverage in the world! Its production process is unique. More on that later. 

Perhaps the closest familiar relative to sake would be beer, in that beer is an alcoholic beverage brewed from a grain.

Premium sake is made from just 4 ingredients: rice, water, koji, and yeast.  
For some varieties, a fifth ingredient there is a small amount of distilled alcohol added.  

In a nutshell, rice is harvested, hulled, polished, rested, then rinsed and soaked, and then steamed. 

After steaming, the rice may go straight into the fermenting tank, or it may be kept aside and used as a substrate upon which a special mold propagated. You read that correctly, mold.

But not just any mold. We are talking the national mold of Japan! This mold, which goes by the name koji, in Japanese and aspergillus oryzae in the scientific community.  See, as the koji grows on the steamed rice, the enzymes it releases converts the starch in the rice into sugar.  It does some other things, too, but for now let's focus on the starch.

When the koji is complete it is ready for use in the brewing process. tossed into the fermentation tank. 

A starter is made with water, finished koji, and steamed rice and the  yeast is pitched. For two weeks (roughly) the yeast multiply and multiply and when it is judged ready, more water, rice, yeast and koji is added in three additions. 

The sugar released from the koji slowly feeds the yeast in the sake mash and the yeast then, slowly produces alcohol from that sugar.

So, it is because sake is made utilizing the the metabolisms of these two microorganisms simultaneously that sake is unique and also contains the highest alcohol level of any fermented beverage.  

This unique process goes by the name of  multiple parallel fermentation.

When fermentation is completed, the mash is pressed through a fine screen to separate solid from liquid, and then, filtered. Water is also added to soften the alcohol level. It is then pasteurized and stored for about 6 months (again, in most cases). It is usually then pasteurized again before it is shipped out from the brewery to us.

This is mile-high view of the brewing process.