Doing Fieldwork on Fermented Foods in the World

(Mar.22-Sep.24, 2022, Nagoya University Museum)

Part 3. Fermented foods as seasonings

In Japan, miso, soy sauce, vinegar and mirin made from rice and soybeans are used as important fermented seasonings that give washoku (Japanese fare) its flavor. In Southeast Asia, though, rather than seasonings produced from grains, fermented seasonings from seafoods, such as fish sauce, are frequently used. In addition, natto, a side dish in Japan, is also used as a seasoning there. The ingredients used in fermented seasonings vary regionally, but seasonings in the Asian food culture zone, where rice is the staple food, are characterized by the demand for the savory “umami” flavor arising from fermentation.

Chapter 7. Is natto a side-dish or a seasoning? A Cross-regional comparison of Natto in Japan and Southeast Asia

In Asia, an “umami culture zone” exists as one food culture zone. It includes a “grain sauce dominance zone” in East Asia, including Japan, in which douchi (Chinese fermented soybeans), soy sauce, miso, and other fermented soy seasoning predominate, and a “fish sauce dominance zone” in Southeast Asia, in which fish sauce, shiokara, and other fermented seafood seasonings predominate. However, there is also an “Asian natto zone” in the laurel forest band extending across the boundary between the grain sauce dominance zone and the fish sauce dominance zone, where natto is used as a seasoning (Fig. 1).

■ Asian natto varieties and ways of using them

The natto of Southeast Asia is divided primarily into two lines, the “Thai line” found in places where people of Thai descent live, such as northern Vietnam, Laos, and Thailand, and the state of Shan and region of Magway in Myanmar; and the “Kachin line” found in the state of Kachin in Myanmar and the Dehong Dai area of Yunnan Province in China. Both varieties of natto are naturally eaten as a side dish with rice, just as in Japan, and they are also used as a seasoning.

Asian natto consumed as a side dish is eaten in different ways depending on whether the rice it is eaten with is glutinous or non-glutinous. Eating natto mixed with non-glutinous rice is the way people who produce natto of the Kachin line enjoy it, and the natto they produce is sticky and stringy, with a taste and appearance almost identical to that of Japanese natto (Photo 1). On the other hand, natto of the Thai line in the northern parts of Vietnam, Laos, and Thailand, where glutinous rice is the staple, is not sticky. It is mixed with chili peppers, salt, coriander, and other ingredients, crushed together and eaten as a dip for glutinous rice (Photo 2).

The main methods of using natto of the Thai line are as seasoning, instead of a side dish. Chili peppers, salt, ginger, coriander, and other ingredients are mixed with crushed natto and dried into a flat form. This is used as a flavoring for fried foods or as a stock for soups (Photo 3). Drying it out stops the fermentation, so it becomes an all-purpose seasoning that can be stored for long periods.

■ Differences between Asian natto and Japanese natto

Japanese natto was used to be produced by making wrappers out of rice straw on which hay bacilli were present, filling them with boiled soybeans and letting them ferment. These days, hay bacilli extracted from rice-straw natto are separated into a pure culture, which is sprinkled over the boiled soybeans which are then allowed to ferment. For Asian natto, rather than rice straw, large leaves of plants growing naturally near where the manufacturer is living are gathered, and the soybeans are fermented using the hay bacilli found on those plants’ leaves (Photo 4).

Asian natto is used not only as a side dish, but also as a seasoning, and a variety of plant leaves serve as the source of the bacilli in its production, so diversity is seen depending on the region. Japanese natto, however, uses only bacilli derived from rice straw, and currently it is used mainly as a side dish, with no diversity in usage. Asian natto, though, also faces competition from other umami seasonings.