Sake Brewing

There are about 1800 Kura (“Saké breweries”) in Japan. In the US, there are presently six Saké breweries, five located in California and one in Oregon. These US Saké breweries include Gekkeikan (Folsom, CA), Kohnan/Hakusan (Napa, CA), SakeOne (Forest Grove, OR), Takara Sake US (Berkeley, CA), Ozeki Sake US (Hollister, CA), Yaegaki USA (Vernon, CA).

SakéOne is the only US owned Saké brewery. The others are all Japanese owned, most being U.S. branches of Japanese Saké breweries. Gekkeikan Brewing in Japan is the #1 Saké brewery in the world. Ozeki in Japan is the #3 Saké brewery in the world. Takara in Japan is the #4 Saké brewery in the world.

My favorite of the US Saké breweries is Kohnan/Hakusan. Of the other US Saké breweries, I generally prefer their higher end Saké, such as the Gekkeikan Horin. I hope to visit the SakéOne brewery in the fall.

Generally, except for some of the largest breweries, the Saké brewing season is about from the end of October to the beginning of April. This is because the colder weather can assist the fermentation process, which needs to occur at lower temperatures. Larger breweries possess the advanced technology to ensure their fermenting tanks remain cold year round.

As the Saké brewing season begins, the brewers usually begin with the lower grades of Saké. As the weather becomes progressively colder, then they will begin brewing the higher grades of Saké. For example, the Ginjo brewing period peaks in January and February.

The Toji, is the head Saké Master of a brewery. There is almost never more than a single Toji in any brewery. All of the other Saké masters and workers are known as the Kurabito, the “people of the brewery.”

Brewing Process

Saké is basically made with only rice, water, koji and yeast. Sometimes a bit of brewer’s alcohol is added as well. Rice is the starting point. Just as grapes are the essential component of wine, so is rice essential to Saké.

The rice used in Saké is special and is not the same as the rice you eat, table rice. There are over 60 different strains of Saké rice and some are considered superior to others. Like grapes, different rice strains also grow best in particular regions. Some famous examples of Saké rice include Yamada Nishiki, Miyama Nishiki, Gohyaku Mangoku and Omachi. Yamada Nishiki is considered by many to be the best of all Saké rice strains. One way Saké rice differs from table rice is that the starches, which get turned into alcohol, are concentrated in the center of the rice grain. Saké rice grains are also usually longer than table rice.

The first step in the brewing process is to polish the rice, in other words, to remove the outer layers of the rice grain. The purpose of this step is to remove undesirable minerals, fat and proteins from the outer layers of the rice grain. The important starches are in the middle of the grain so the closer you get to that center, the better. The polishing must be done carefully to avoid cracking the kernels. The amount of the rice grain that remains after polishing is known as the “Seimai buai” percentage.

After polishing, the rice is washed to remove all of the remaining rice powder, the nuka. Afterwards, the rice is soaked to bring its water content to a desirable level. At this stage, it is important to use good water as its quality will affect the eventual final product. Good, pure spring water is commonly used at this stage. Once the water content is sufficient, the rice will be steamed until it attains a firm consistency.

Some of the steamed rice will now be set aside and used to make the important koji-kin, the koji mold, an enzyme. This process takes about two days to complete. The role of koji is to convert the starches into sugar. This is a delicate stage and requires much attention.

Once the koji has been created, a yeast starter, called moto or shubo, is produced with water, rice, koji and yeast. An important decision at this stage is the choice of yeast. There are many different types of yeasts, with various qualities that can provide different flavors to the Saké. Some yeasts are proprietary secrets, closely held by the brewery. Much will depend on the type of Saké the brewer wants to create.

Once the starter is completed, it is added to a large vat where the Saké will actually be fermented. Over the course of about four days, the steamed rice, koji and water will be added to the vat in three stages. This creates the fermentation mixture, called the moromi, and it will ferment for about 18 to 32 days. This process is known as multiple parallel fermentation because as the koji converts the starch to sugar, the yeast converts the sugar to alcohol. This is a significant difference from wine and beer, which both undergo only a single fermentation process.

When the fermentation process is completed, the sake will usually be pressed, separated from the lees. It may then undergo another filtration process. Next, it is usually pasteurized, temporarily heated to deactivate the enzymes which could potentially mar its taste. At this point, water is also added to dilute the Saké. After fermentation, the Saké has an alcohol content of about 20% alcohol but it will be diluted until the content is reduced to about 15%.

The Saké is then bottled and screwtops are used as closures. Screwtops are used because Saké is generally not meant to be aged and the cork could discolor the Saké. After bottling, the Saké will commonly be stored for six to eighteen months before being shipped. It is rarely stored longer than that and sometimes may be shipped without any storage time at all.

Once you purchase a bottle of Saké, you should keep it somewhere cool and dark. Light and heat are enemies to Saké. If kepy cool and dark, most Saké should last for up to a year without losing any flavor. Only Namazake needs refrigeration and it probably should not be kept more than a few months as it was not pasteurized.