Miso

Miso is a thick, fermented paste that serves as a traditional Japanese seasoning. It is made by fermenting soybeans with salt and a fungus called *Aspergillus oryzae* (known as kōji), often along with ingredients like rice, barley, or seaweed. This versatile paste is used in sauces, spreads, and pickling—for vegetables, fish, or meat—and is a key component of miso soup, a staple in Japanese cuisine, when mixed with dashi broth. Rich in protein and minerals, miso was an important source of nutrition in feudal Japan.

The exact origins of miso in Japan are unclear. Fermented grain and fish pastes, known as jōmon miso, were made as far back as the Neolithic Jōmon period (14,000–300 BC), similar to early soy- and fish-based sauces across East Asia. A predecessor from China appeared in the third century BC, and fermented soy foods like *hishio* likely arrived with Buddhism in the sixth century AD. By the Nara period (710–794), a version called *mishō* or *mishou* emerged, with *hishio* still referring to beans; the name is thought to have shifted 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 with whole, unground soybeans, resembling nattō. During that era, Buddhist monks discovered that grinding soybeans into a paste allowed new ways to flavor other foods, and homemade miso—called *temaemiso*—became widespread due to its simple production. Miso was used as military provisions in the Sengoku period, and daimyōs considered its production an important economic activity. In the Edo period (1603–1868), miso was also called *hishio* and *kuki*, and regional varieties developed to suit local climates and cultures. Today, most miso is made industrially, with traditional homemade versions becoming rare. Recent years have seen new types, including those with added soup stocks, calcium, beans other than soy, or reduced salt.

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

The taste, aroma, texture, and appearance of miso vary by region and season, influenced by temperature, fermentation time, salt content, the type of kōji, and the fermenting vessel. The most common flavor categories are *shiromiso* (white miso), *akamiso* (red miso), and *awasemiso* (mixed miso). While white and red are the most widespread, preferences differ by region: darker akamiso is popular in the eastern Kantō region (including Tokyo), while lighter shiromiso is favored in the western Kansai area (Osaka, Kyoto, Kobe). More specifically, *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 a whitish type from Kyushu, western Chugoku, and Shikoku, with a reddish variety found in northern Kanto; it has a distinct smell. *Mame miso* (soybean miso) is darker reddish-brown, less sweet, with some astringency and strong umami, requiring a long maturation. It is mainly consumed in Aichi, Gifu, and Mie prefectures. Grain-free soybean miso is also called *hatchō miso*, a specialty of Okazaki, Aichi, with origins in Mikawa Province during the Sengoku period, still made using large wooden barrels and stones on the lid. *Chōgō* or *awase* miso (mixed miso) combines different varieties to improve weaknesses; for example, very salty mame miso becomes milder when blended with kome miso.