Ask not what natto can do for you

Hone-shaburi, literally sucking on bones, is a Japanese expression roughly equivalent to have been "bled dry" in English. This name has been humorously applied to the book review column in Weekly Playboy magazine. Which in its May 27 issue reviews a book titled Natto no Shokubunka-shi (The Food Culture History of Natto), a 301-page hardcover book by Satoshi Yokoyama.

Yokoyama holds a PhD in science and is known in academic circles for his geographical study on the basis for existence of mountainous villages in northern Laos. 

Natto are fermented soybeans, which along with tofu and miso, is one of the three main sources of vegetable-based protein in the Japanese diet. They are to a large extent a regional food consumed in east Japan, being less common in Kansai, Shikoku and Kyushu. 

Despite their nutritious properties and comparatively low cost, natto have a reputation for being widely reviled by non-Japanese, many of whom find their ammonia-like smell and gooey consistency somewhat repugnant.

The photo accompanying the review shows a pair of chopsticks lifting a blob of beans from a bowl trailing threads in their wake -- underscoring natto's slimy consistency. The caption reads, "The first record of natto in Japan dates back to the Taiho Ritsuryo (Taiho Code) of 701 CE. According to a familiar legend, the method for producing natto is credited to Prince Shotoku." 

The book under review was published in 2021 by Saitama-based Nozan Gyoson Bunka Kyokai. The reason for the three-year delay might be due to a revived interest in natto following the recent wave of price increases affecting foodstuffs.

According to Shokuhin Shimbun (Feb 23), a trade publication covering the food industry, natto have been on a roll. Despite price increases of 6 to 7% imposed by manufacturers earlier this year, the sales volume has been largely unaffected, probably because retail prices for most natto products remain in the "two-digit range," i.e., below ¥100 per pack.  

Meanwhile, Shokuhin Shimbun reported that major manufacturers have been working to develop new value-added products with additional health claims, such as Mizkan's "Natto Effect Intestinal Care," which was released last February. 

The book reviewer begins by stating that he always stocks natto at home, preferring it as an inexpensive and convenient source of protein. Typically it is consumed atop a bowl of steaming rice, although for variety it can be eaten atop buckwheat noodles or pasta.  

The reviewer cites a book he read advising that the organic nutrients in natto are killed when heated above 60 degrees Centigrade, so cooking at high temperatures is to be avoided. 

Consumption of soybeans fermented with a type of bacteria present in straw are by no means exclusive to Japan, he writes. They can be found in Korea, and from Nepal to Vietnam, in Indonesia, and in countries as far away as west Africa. In Myanmar, the beans are used as a seasoning, or can be baked into patties that can be preserved. 

From this it is apparent that Japan may only be unique in that it consumes natto almost exclusively in an uncooked state. This leads the reviewer to ponder the paucity of variation in methods of consuming natto. 

Since the modern Japanese diet is so diverse and competition so fierce, why not be content to limit natto consumption to being plopped atop a bowl of steaming rice, and leave it at that? Well, just as birds living on isolated islands without natural enemies tend to evolve with larger physiques, the natto food culture has assumed a greater presence in its geographic area owing to its lack of competitors. 

That said, variations on natto consumption have evolved, albeit on a limited basis. For instance, in northeast Japan, natto is utilized to make a soup, natto-jiru. In Daisen, a city of 72,000 in southern Akita Prefecture, mashed natto are blended with miso or soup stock for use as a condiment. And the inhabitants of coastal areas of Akita use it to produce a fish sauce called shossuru.

These variations, prepared by residents in the inland mountainous parts of the prefecture, somewhat resemble the ways soybeans are consumed in other Asian countries.

Since the Japanese diet has no lack of sources of protein, where does that leave natto? Mainly, it would seem, as a health food. Natto is an inexpensive source of dietary fiber, protein, minerals and vitamins. Along with polyamine, an organic compound with anti-aging restorative properties, it boasts numerous other beneficial ingredients.

Still, without more variation, writes the reviewer, natto may someday find itself at a dead end; to avoid this, the reviewer suggests, makers need to study foreign models and experiment with new products.

© Japan Today