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 6. The science of padaek, a taste of Laos

To obtain nutrients when eating rice well, eating “side dishes” at meals is essential. Laos is a land-locked country with no access to the sea, but freshwater fish taken from rice paddies, ponds, rivers, and so on are eaten daily as a side dish with rice. Since high-quality salt can be obtained from rock-salt beds underground, the people in this region have added salt to the freshwater fish at hand since ancient times, fermenting it like Japan’s shiokara to produce the fish sauce called “padaek.” They use it as a preserved food and a seasoning in cooking.

■ A taste of Laos, padaek

Dishes using padaek are truly diverse, including salads, soups, and broiled foods, or as a dip for vegetables or rice like moromi miso is in Japan. It is well matched with the staple food of glutinous rice. Combining umami and saltiness, it has a tastiness that makes one want to keep eating it and a familiarity among the Lao people, who treasure padaek as “our family’s taste, our hometown’s taste” and an all-purpose seasoning, reminiscent of miso and soy sauce in Japanese cuisine.

In Laotian villages, the custom of producing and eating homemade padaek continues even now. Also, fresh markets in towns are lined with shops specializing in padaek, where the product is sold in bulk or in bottles, with anticipations of development into a fermented food industry representing the nation.

■ How is delicious padaek made that keeps well?

The way to make traditional padaek according to a farming family in Vientiane, the capital of Laos, is to mix fish, salt, and rice bran at a 3:1:1 ratio by weight, put it into a container and keep it for about two to three months with the lid on. From long ago it has been said that the longer you keep it (six months to a year or more), the tastier it becomes.

Recently, the rapid economic growth and modernization in the cities has had an impact on rural areas as well, and there are concerns about the traditional knowledge and manufacturing methods regarding padaek dying out. As scientific understanding of the ingredients microorganisms active in the fermentation of padaek advances, the propagation of fermentation control technology could stabilize and further increase the quality of the product without the sole reliance on intuition and experience from the past, while preserving the traditional manufacturing methods.

For the first one or two months of padaek’s fermentation, lactic acid bacteria of the genus Tetragenococcus that thrive under highly saline conditions (15-20%) produce lactic acid, giving rise to an acidic environment that effectively suppresses unwanted bacteria. Similar lactic acid bacteria have been found in the fermentation of Japanese miso, soy sauce, and fermented squid.

During the long process of fermentation that takes six months to a year, the proteins in the fish are broken down into amino acids. The umami component glutamic acid and the essential amino acid lysine are particularly prevalent, and ornithine, which is said to be good for health, is also present in it. By adjusting the salinity to about 15 to 20% in accordance with the traditional manufacturing methods, the production of histamine, which causes allergic-type food poisoning, can be suppressed.

The Japan International Research Center for Agricultural Sciences has been collaborating with universities and research institutes in Laos and introducing the results of research on padaek fermentation as “Ways of making delicious padaek that keeps well” to farmers and padaek manufacturers in Laos. A deeper understanding of the traditions, quality, and microorganisms of fermented foods is anticipated along with developments in fermented food research where the past is studied to learn new truths that will be useful in people’s lives in the future.