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Jan 25, 2023

FOOD NEWSMeeting a Producer – Hayakawa Shoyu Miso Co., Ltd.: History and Manufacturing Methods of Soy Sauce and Miso

Kazuhiko Toyama of Hayakawa Shoyu Miso Co., Ltd., which was founded 138 years ago and has a manufacturing plant in Miyakonojo City, Miyazaki Prefecture. He holds the qualifications of "First Grade Certified Miso Production Skilled Worker" and "HACCP Dissemination Instructor" and works for the company as Director and General Manager of the Manufacturing Department. In this article, we interview Mr. Toyama about the famous traditional Japanese fermented foods of soy sauce and miso, the history of their development, and their manufacturing methods.

Jan 25, 2023

Please tell me about the miso and soy sauce you produce.

Miso and soy sauce are traditional fermented foods in Japan. Miyakonojo City in Miyazaki Prefecture, where our company is located, is in southern Kyushu. Miso is popular mainly for barley miso, and soy sauce is popular mainly for mixed soy sauce. Barley miso is made by adding malted barley to soybeans. Mixed soy sauce is a soy sauce made by mixing concentrated amino acid liquid with a liquid called kiage, which is made by squeezing “moromi,” which is made by maturing soybeans and wheat.

Why is barley miso the mainstream in Kyushu?

In Kyushu, there has been a custom of making rice in summer and barley or wheat in winter, which is a way of using fields called two-crop farming. Even now, Saga Prefecture and Fukuoka Prefecture, which are the breadbasket areas, are the second and third largest producers of barley and soybeans in Japan. There used to be a lot of barley, so Kyushu has a lot of miso made with it. On the other hand, there are many rice production areas in cold regions such as Tohoku and other northern regions, and good quality rice is produced. There is a culture in Kyushu that rice is a high-grade product, and that it is wasteful to use it as a raw material for miso. It is said that this is why barley miso was made with a lot of barley.

I have an image that Kyushu soy sauce is sweet. Why is that?

It is said that in Japan, main foods are sweeter and less salty in hotter and more southern areas, and they become saltier in colder, more northern areas. There are also differences in the way soy sauce is used, especially in southern Kyushu, where people say they “eat soy sauce.” In the warm sea area where you can catch a little watery fish, you can enjoy the taste of the ingredients by dipping them in soy sauce and mixing them together, rather than tasting them with a little soy sauce putting on them. That’s why people in the south prefer to eat sweet foods rather than salty foods, and it seems to have been passed down until now.

But now, nationwide, people have a little sweet tooth, and sweet soy sauce and sweet miso are gradually being accepted. As for miso, a little sweet barley miso is made nationwide in the form of awase miso, and it has become easier to be accepted by people outside Kyushu.

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In the first place, why are miso and soy sauce made in the same factory?

In Japan, miso and soy sauce are often made in the same place. A long time ago, the first thing called jiang, or hishio in Japanese, was made in China. In China, there was a long period of civil war called the Spring, Autumn, and Warring States period, and many long-lasting foods were made to bring to war. It is said that about 700 years ago, hishio made from grains was introduced to Japan from China, and it separated into miso and soy sauce. Hishio using fish has been imported to Southeast Asia and become nam pla. The hishio made of cereals introduced to Japan is originally solid, and liquid floats on top when matured. It is called “tamari” and it is said that it developed as soy sauce because it tasted good when licked. Miso and soy sauce are made from the same ingredients and have been introduced together, so it is common to make them in the same factory even now.

In Japan and various countries in the world, was there a background that fermented food that lasts long was accepted?

There also used to be many civil wars in Japan. The food that soldiers bring there must last. For example, salting it and taking it to the battlefield. In fact, however, miso and soy sauce seem to have been appreciated, and it is said that they were spread only gradually. It seems to have been a high-class food in the past, so it was hard for the general public to eat it. Then, around the Edo period, common people became able to eat it by large-scale production. If you look at a big company today, it’s like Kikkoman. It is said that such companies started to make miso and soy sauce on a large scale by using koji at the end of the Edo period.

Also, I don’t know where the origin is, but there are fermented foods all over the world. Not only in Europe, but in Korea it is kimchi, and in Southeast Asia it is nam pla, and they are scattered across the world. I think that fermented food has been passed down among people around the world.

When hishio developed into miso and soy sauce in Japan, were there any unique features that were affected by the climate of Japan?

For example, Thai nam pla has strong scent as you know. The smell of the food in the area is strong, so they say that it’s to get rid of it. Why didn’t Japanese miso and soy sauce have such a strong smell? It is said that this is because they have developed to have a delicate fragrance in accordance with Japanese ingredients.

I think it is also unique to Japan to make koji in the manufacturing process. Koji is a grain with koji mold. Among koji mold, a mold called Aspergillus oryzae is attached to grains to make enzymes to break down starch and protein in grains. The enzyme is koji that breaks down the components of soybeans.

In other areas, fermented foods are often fermented by just adding all the ingredients and fermenting seeds. However, in Japan, koji is originally made to produce enzymes for fermentation, and the quality is made uniform by preparing it. I think Japanese miso and soy sauce are characterized by their delicate making.

Please tell me the manufacturing process of miso briefly.

Miso is made from soybeans, grains and salt. There are many companies in Japan, but there is only one recipe that has been handed down from old times. First, we make koji. The koji made from barley is called mugikoji or malted barley, and the koji made from rice is called komekoji or malted rice. We mix the koji, steamed soybeans and salt and put it in a tank, barrel or pot. Then we mature it until amino acids of soybeans are decomposed, and that becomes miso. That’s the general flow. Both rice miso and barley miso have the same process.

Is there any difference in the maturing period of miso?

It’s a little technical, but the maturing period is decided by the ratio of the amount of koji and soybean. The fermentation process involves breaking down soy protein into amino acids, so-called umami ingredients. It is made by calculating the period in which it is broken down completely and becomes all umami. The longer the maturing period is, the darker the color becomes by the coloring reaction called Maillard reaction. Just as the skin gets sunburned, the longer the period is, the darker the color becomes. As for southern Kyushu, white miso is preferred, so it will be sold in a short maturing period. For example, the amount of malted barley is increased and the amount of soybeans is decreased, so that all soybeans are quickly decomposed to make miso. So, the difference in the maturing period corresponds to the difference in the ingredients of umami and the color.

On the other hand, how about soy sauce?

Soy sauce is made from the same ingredients as miso: soybeans, grains and salt. By regulation, salt is salt water. So, you can think that the ingredients and the manufacturing method are the same as miso in that regard, as the difference is only solid or liquid. However, the difference is that wheat is used to make soy sauce, not barley. In the case of naturally brewed soy sauce, steamed soybeans and wheat are malted, mixed with salt water and put in a place like a pool. It is stirred periodically and aged for about 10 to 12 months. The matured product is called “moromi,” and the squeezed liquid is called “nama-shoyu” (raw soy sauce) or “kiage.” In the case of Kyushu, in fact, the mixed soy sauce which is made by mixing the liquid which decomposes the enzyme of soybean and corn and extracts the umami is sold in the general shops.

How do you want those outside Japan to use miso and soy sauce?

Miso made in Japan is often finished in the best condition to make miso soup. However, I don’t know if people overseas drink soup with it. It may be different depending on the countries. Also, for example, the sense of deliciousness might be different from Japan.

To be honest, I want people to use it primarily for miso soup. However, it is also good to use it adeptly as a seasoning in addition to the sauce that is suitable for local dishes. I think the good point of miso and soy sauce is that they can be used as seasoning. I think overseas people would like them more if they use them freely like that.

Lastly, please tell us about your thoughts that developed while you work in this company.

I’ve been working here for about 28 years now, and I’ve had my skills hammered into me by many seniors. When we were young, the way of learning is just “look and remember.” Therefore, the current issue is how to inherit the skills. Now, we are working with Senior Managing Director Hayakawa of our company to develop a manual. But it’s difficult. The reality is that the taste of koji changes depending on the person who makes it. Our goal is to make it as uniform as possible, and we are promoting the manual making and data collection. And I want to develop many wonderful juniors by doing that hard. I think that is my current dream, or rather, my responsibility.

Hayakawa Shoyu Miso Co., Ltd.

Address: 3732, Nishimachi, Miyakonojo, Miyazaki, Japan, Zipcode 885-0076

Telephone: 0986-22-0241