Miso

Miso is a thick, fermented paste that serves as a traditional Japanese seasoning. It is made by fermenting soybeans with salt and kōji—the fungus *Aspergillus oryzae*—and often includes ingredients like rice, barley, or seaweed. This paste is used in sauces, spreads, and pickling, and is a key component of miso soup, a staple dish in Japanese cuisine. Rich in protein and minerals, miso was an important source of nutrition in feudal Japan.

The exact origins of miso in Japan are unclear. During the Neolithic Jōmon period (14,000–300 BC), grain and fish-based misos, known as jōmon miso, were already being made. A similar fermented soy product likely came from China around the third century BC, and fermented soy foods such as *hishio* probably arrived in Japan with Buddhism in the sixth century AD. By the Nara period (710–794), a precursor called *mishō* or *mishou* existed, and the word is thought to have evolved from *misho* to *miso*. In the Kamakura period (1185–1333), a typical meal included rice, dried fish, miso, and a fresh vegetable. Until the Muromachi period (1337–1573), miso was made without grinding the soybeans, resembling nattō. Buddhist monks then discovered that grinding soybeans into a paste allowed new ways to flavor other foods. Homemade miso, or *temaemiso*, became common, and during the Sengoku period, it was used as military provisions, with daimyōs treating miso production as an important economic activity. In the Edo period (1603–1868), miso was also called *hishio* and *kuki*, and regional varieties emerged. Today, most miso is industrially produced, and traditional homemade versions are rare. New types have appeared, including those with added soup stocks, calcium, non-soy beans, or reduced salt.

Miso can be made from a mix of soybeans, barley, rice, buckwheat, millet, rye, wheat, hemp seed, or cycad. Producers outside Japan now also use chickpeas, corn, azuki beans, amaranth, and quinoa. Fermentation times range from five days to several years. Japanese miso is commonly classified by grain type, color, taste, and background. Varieties include *mugi* (barley), *tsubu* (whole wheat or barley), *genmai* (brown rice), *moromi* (chunky with unblended kōji), *nanban* (with hot chili pepper), *taima* (hemp seed), *sobamugi* (buckwheat), *hadakamugi* (highland barley), *nari* (cycad pulp, used in Buddhist temple diets), and *gokoku* (five-grain: soy, wheat, barley, proso millet, and foxtail millet). Many regions have their own variations; for instance, Sendai miso uses coarsely mashed soybeans. Rice-based misos like *shinshu miso* and *shiro miso* are called *kome miso*.

Miso’s taste, aroma, texture, and appearance vary by region and season, influenced by temperature, fermentation time, salt content, kōji variety, and the fermenting vessel. The most common flavor categories are *shiromiso* (white miso), *akamiso* (red miso), and *awasemiso* (mixed miso). In eastern Japan’s Kantō region, darker akamiso is popular, while in western Kansai (Osaka, Kyoto, Kobe), lighter shiromiso is preferred. *Kome miso* (rice miso) can be yellow, yellowish white, or red; whitish versions use boiled soybeans, reddish ones use steamed soybeans. It is more common in eastern Japan, Hokuriku, and Kinki. *Mugi miso* (barley miso) is whitish and produced in Kyushu, western Chugoku, and Shikoku, with a reddish variant in northern Kanto; it has a distinct smell. *Mame miso* (soybean miso) is darker reddish-brown, less sweet, with astringency and strong umami, and requires long maturing. It is mainly consumed in Aichi, Gifu, and Mie prefectures. Grain-free *hatchō miso*, an Okazaki specialty, is made using large wooden barrels and stones on the lid, a method unchanged since the Sengoku period. *Chōgō* or *awase miso* (mixed miso) combines different varieties to improve weaknesses—for example, blending salty mame miso with kome miso yields a milder result.