Akashi Sake Brewery co.,ltd
Office
9-48,Funage-cho,
Akashi-city,Hyogo
673-0026, JAPAN
Phone +81-78-923-2727
Fax +81-78-923-3277
The koji, or malted rice, determines how a sake will taste. Koji is made by causing koji mold to proliferate on steamed rice. Maintaining the optimal temperature and humidity for the mold to grow requires skill born of years of experience and finely tuned intuition. The preparation of the koji is considered the most crucial step in brewing sake. Koji mainly acts to convert the starches in the rice to sugars, a process called saccharification.
The moromi is made by adding steamed rice, prepared koji, and water to the shubo yeast starter. Sake production is quite unusual among brewing processes worldwide, in that saccharification of the starches in the rice and fermentation take place simultaneously. Once the additions are made, the mixture is known as moromi until the pressing step that separates the sake from the sake lees.
The shubo, or moto, as it is also known, is a yeast starter made by adding a carefully selected yeast to plain steamed rice, water, and prepared koji. The purpose of making the shubo is to cultivate as pure a yeast starter as possible for use in the fermentation of the sake. Because the quality of the final sake is affected by the quality of the shubo, the preparation of the shubo is considered a fundamental step in brewing sake.
Additions are made to the moromi in three stages
— a first stage called hatsuzoe, a second stage called nakazoe, and a final stage called tamezoe. This three-part process, unique to sake brewing, helps inhibit the growth of unwanted bacteria while it aids in yeast propagation. It also makes it easier to control the temperature of the moromi.
The kobo, or yeast, acts to convert the sugars generated by the oxygen in the koji into alcohol molecules. Also, the fragrance special to ginjo-shu and other premium sakes is mainly created by the action of the yeast, and thus, the role of the kobo plays a very important part in the overall sake production process.
The last step in brewing most sakes is hi’fire, or pasteurization. Heating the new sake at a relatively low temperature of 50 to 60 degrees Celsius kills off unwanted bacteria that can adversely affect the flavor and quality of the sake. The hi’fire process is very effective and was in use in Japan long before Pasteur discovered that heating could kill bacteria.
Hyogo Prefecture has been a center for sake production since the Tokugawa Period (1600–1867), partly due to locally grown rice varieties being particularly suited to brewing sake. Growers developed the Yamada Nishiki strain in 1923 as the result of a cross-breeding and improvement process. Beginning in 1936, the Yamada Nishiki strain began to be widely used in making sake. Today it is the most popular variety of rice for sake-brewing, and is used by brewers all across Japan. It is said that even another hundred years of rice development will not produce a strain to beat Yamada Nishiki.
Yamada Nishiki, the ultimate rice for sake production, has the following characteristics:
1.Individual grains are large.
2.The starchy center, or shinpaku, makes up a large proportion of each grain.
3.The strain has low protein and lipid content.
The term shinpaku — the two Japanese characters mean“heart” and “white” — refers to the white color of the starchy center. But although the shinpaku makes up a large proportion of each grain, the starch does not have a dense structure. Rather, the starch molecules are loosely grouped, allowing koji mold spores to easily enter the structure. This in turn helps produce superior koji, or malted rice. The best Yamada Nishiki rice is grown in Tojo Town, Miki City, and the surrounding region located about one hour north of Akashi by car.
