Travel Series: Aichi, Japan, Maruya Hatcho Miso

〒444-0923 愛知県岡崎市八帖町往還通52
52 Hatchocho Okandori, Okazaki 444-0923, Aichi Prefecture

Miso is an essential ingredient in Japanese cooking and while there are many different types of Miso available in each region, they can be categorized into rice, soy beans or barley Miso. To make the starter culture, rice, soy beans or barley are inoculated with a fungus called Koji. The scientific name for Koji is Aspergillus oryzae, and it is known as the “national fungus” of Japan. It is essential in making not just Miso, but also soy sauce, Saké, vinegar and Shochu. Rice Miso is more common in the northern and central regions of Japan, where rice production is more abundant. Barley Miso is more common in the southern island of Kyushu as well as Shikoku, and soy bean Miso is limited to Aichi prefecture and its surroundings, which is located in the mid-southern part of Japan.

The basic method of making Miso is by steaming the main ingredient and inoculating it with Koji. That starter culture is then combined with salt and soy beans, and left to ferment (and sometimes age). You may hear the terms “white Miso” and “red Miso”, which are based on the appearance. The color difference is greatly affected by the amount of Maillard reaction (amino acids react to the natural sugars). These different Misos are used in different applications depending on the desired characteristics.


Hatcho Miso is a red Miso (“Aka Miso”) and is made with 100% soy beans (with salt and water as well). Maruya was established in 1337 and is the oldest Hatcho Miso producer that still exists to this day. They are located in Okazaki, which is about a 30 minute train ride east of Nagoya in Aichi prefecture (Chubu region). I was fortunate to be introduced to Maruya Hatcho Miso through work, and even more fortunate to meet the President of the company, Nobutaro Asai. He is a very passionate and interesting figure, who has worked very hard to promote his Misos around the world. It is important for Japanese businesses to bring their products overseas because of Japan’s aging population. For them to survive, they need to capture the interest of non-Japanese customers. Miso has become a familiar food item for many Americans, but Hatcho Miso is still a novelty. It is a very dense Miso that has more Umami and a lower salt content compared to other types of Miso. In Nagoya and Aichi prefecture, this Miso is often stretched out with sugar and Mirin, to make regional dishes such as Misonikomi Udon and Miso Dengaku (a sweet Miso sauce served over eggplant, Konnyaku etc.). Hatcho Miso is also used to make Aka Dashi Miso Soup, which is often made with Shijimi (tiny clams).

To make Hatcho Miso, the soy beans have to be steamed, formed into balls, then inoculated with Koji (takes four days). Images can be seen here. The Koji soy bean balls are then combined with sea salt and spring water, then placed in large wooden barrels. The craftsmen will then step on the soy bean mixture to pack them in and remove any air pockets. Once done, four tons of large rocks are stacked on top of the lid to pack in the soy beans even more and squeeze out the excess water (hence the lower salt content). The stacking of the rocks requires a lot of skill, and only a few people have these skills to carry out the task. It is then left to ferment and age for two years. The result is a very dense, earthy and Umami rich Miso. In my opinion, Hatcho Miso complements root vegetables, mushrooms and game meat, and it also pairs well with dark chocolate. I think it is a great ingredient that can be used in non-Japanese food to enhance Umami and add depth to braises and stews.



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