1. On the release of "Taketsuru Sakémakers"

Sake is made through many processes, and there are many options at each stage: the type of rice used, the type of yeast used, whether to use the kimoto method or the fast brewing method, whether to use pure rice or add alcohol, etc. Sake brewers make their choices based on the type of sake they want to make.

This time, a new option called "flat rice polishing" has been added to the previously only one rice polishing method. On this page, we will introduce the background of Taketsuru Sake Brewery's adoption of this new rice polishing method. We hope that you will feel closer to how we plan our sake brewing.

2.What is the purpose of polishing rice?

Whether it's rice for eating or sake, it is polished to remove the bran so that it is easier to digest and ferment. In the case of sake, the rice is polished even after the bran is removed. Even though the bran has been removed, rice has the characteristic that the closer to the surface it is, the more protein there is, and this protein causes an unpleasant taste when the sake is made. For eating, about 10% of the rice is removed, which corresponds to the bran, while sake usually has more than 20%, and some daiginjo sakes, which aim for a clean taste, have more than 90% removed.

[Schematic diagram of rice protein distribution]

It gets smaller towards the center

3. What is “flat rice polishing”?

Rice has a long, elongated shape. Conventional rice polishing methods mainly polish the long vertical direction, and do not polish the short horizontal or depth directions very well. Since rice protein is distributed evenly from the surface regardless of the length and width, it cannot be said to be efficient if the width and depth cannot be polished .

brown rice

Conventional rice polishing (spherical rice polishing)

(Source: Satake Corporation)

So we came up with the idea of changing the way the rice polishing machine is controlled to polish the rice in the depth direction. If we could polish the rice in the depth direction, we could remove the protein efficiently without polishing the rice vertically too much.

This method of polishing rice is called "flat polishing" because the shape of the polished rice is flat. In contrast, the traditional method is called "spherical polishing" because of its appearance.

Flat polished rice

(Source: Satake Corporation)

4. Satake's new rice milling machine

In fact, flat rice polishing itself is not a new method, and was proposed by Tomio Saito, a technical officer at the National Tax Agency, in the 1990s. However,

・High level of technology is required to control the rice milling machine

・The time required for polishing rice is too long

Due to these and other issues, only a small number of sake breweries have adopted the system.

In 2018, a new rice polishing machine developed by Satake Corporation, based in Higashihiroshima, Hiroshima Prefecture, overcame these challenges in one fell swoop. Flat rice polishing has finally become a reality, and Taketsuru Sake Brewery has begun considering adopting this new technology.

Problems with flat-polished rice →

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