Often compared to funky washed cheeses or stinky socks, nattō gets a bad rep in the smell department, but is undeniably packed with probiotics and protein, thus a perfect breakfast food to get you started on your day.

Nattō aficionados (including me) would take exception to the maligning descriptions of nattō’s aroma or its sticky characteristic once whipped up to a wonderful slimy mass. We embrace its fermented nose and are addicted to its nutty, yet sharply complex flavors. The feat of guiding a tenuous clump of these lovely fermented beans from bowl to mouth can be daunting for the uninitiated, especially since the gossamer nattō “threads” created seem to take on a life of their own. But that, too, becomes a joy.

Freshly fermented, organic, small-batch nattō has a completely different profile from your run-of-the-mill mass-produced kind. A couple of decades ago, it was still possible to procure organic green, brown and black nattō at a local, upscale supermarket. No longer.

Instead, Yamaki Jozo, an organic soy sauce, miso, tofu and pickle company had been my main source for organic nattō for many years until their nattō supplier retired a few years ago. It took Yamaki Jozo about two years to develop a relationship with another local maker that produced nattō at the high standard required to be sold under the company’s organic label. During those two years, I never ate nattō.

Shimonita Natto, Yamaki Jozo’s new supplier, is located right off the Shimonita exit of the Joshin-etsu Expressway. The town of Shimonita is in Gunma Prefecture and is well-known for three things: nattō, negi (Welsh onion), and konnyaku (devil’s tongue). My coffee roaster/fermenting geek nephew was visiting for a few days so I thought a trip to see how nattō was made would be fitting. We had introduced him to nattō on a previous visit, 13 years ago, and as a vegetarian, protein-rich nattō had become one of his staples. (Megumi Nattō in Sebastopol, California produces lovely organic nattō.)

By good fortune, the morning we visited was the first day of work for Miyu Arai, and the ebullient owner Takamichi Nanto enthusiastically walked the three of us newbies through the process of making nattō. It was clear he loved his metier and that he was a natural-born teacher. According to Nanto, “Washoku (Japanese cuisine) is the food culture of eating soybeans with rice.” Indeed, there is a long history of growing soybeans around the edges of the rice fields because the crops are symbiotic.

Donning paper masks, coats, and hairnets, we trouped along to the anaerobic production rooms. At Shimonita Natto, 210 kilograms of soybeans are steamed and fermented each day and all steps in the production process are done by hand. In the main room, a half-dozen masked workers suited head-to-toe in white hooded coveralls move in synchronization as they scoop the fermented beans into kyōgi (pine paper) which are then folded into triangular shaped packages after weighing. Getting the nattō folded in the kyōgi, packed in cellophane wrappers and stored in the walk-in refrigerator as swiftly as possible is the main priority. Once in a cool environment, the fermented beans become dormant, thus slowing (though never fully halting) fermentation and increasing shelf life.

Each day, eight varieties of soybeans are first soaked overnight, then steamed at 100 degrees celcius for 90 minutes until soft, before being inoculated with nattō spores. The beans are spread out on wooden trays and left to ferment in the fermenting room (muro) for 23 hours at 41 degrees, thus encouraging the prized neba neba (sticky) texture that characterizes nattō.

Workers take turns sleeping at the factory to check on the delicate concoction throughout the night, ensuring that the temperature stays constant for optimal propagation of the spores.

As a teacher and cook for Japanese children, I incorporate nattō into any number of dishes: a particular favorite is fried rice strewn with nattō and a squiggle of mayonnaise. The classic way to eat nattō is whipped up to a creamy mass with seasonings such as Japanese mustard and soy sauce and maybe some chopped scallions, spooned over a small bowl of rice, but nattō is also a perfect vehicle in which to drop freshly pounded mochi (glutinous rice cakes) at New Year’s.

A light scattering of non-agitated nattō beans enlivens and enhances a vegetarian pizza, and nattō can be blended into mayonnaise for a rich, yet complex dressing for composed salads. When first trying nattō, it’s best to start with a measured amount, eaten in a familiar way (such as on a pizza) using the freshest small-batch nattō available.

Always concerned with traditions being carried on, at the end of our tour I ask Nanto, head of Shimonita Natto, if he has someone to take over. His eyes light up and he tells me he has a son working with him, but then laughs and, turning to his new worker, says, “But maybe it will be Arai! Whoever loves nattō will be the next president!”

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