Inspired by the recent “Fermentation Tourism Nippon” exhibition in Tokyo, in which “fermentation designer” Ogura Hiraku introduced a fermented comestible from each of Japan’s forty-seven prefectures, I took a train the short distance from Yokohama to Kawasaki to seek out the product selected by Ogura for the prefecture where I live, Kanagawa. The product is, according to Ogura, Japan’s only fermented confectionery. It’s a rare treat which, for reasons that became apparent, is firmly rooted in place.
Kuzumochi is said to have been serendipitously discovered in the neighborhood of Kawasaki Daishi temple more than 150 years ago when a Mr. Kyubei’s forgotten barrel of rain-damaged wheat flour was found to have separated. Kyubei discarded the gluten but experimented with the converted starch to create a mochi-type sweet which he presented for appraisal to the head priest of the temple. The priest found the magical new product to his liking and blessed it with the name “kuzumochi,” adding the lucky character ju (zu), meaning “long life,” to the Ku of the mochi creator’s name.
The story of the sweet’s fortuitous discovery is well known. However, kuzumochi’s popularity and long-standing close connection with the Kawasaki Daishi temple neighborhood may owe more to the opening nearby in 1914 of an Ajinomoto factory for the production of monosodium glutamate (umami), in which process wheat starch is an unwanted byproduct. Whatever the case, there are eight or nine small-scale kuzumochi manufacturers with cafés in the vicinity of the temple, all competing for custom, which on the weekday lunchtime when I visit is all but non-existent.
Kuzumochi is made by allowing the starch separated from gluten in wheat flour to ferment for about thirteen months. The fermented starch is carefully rinsed with water to remove its characteristic sour smell and then steamed in shallow trays to the desired level of firmness. No additives are used in the sweet’s production, meaning kuzumochi has a shelf life of less than three days. (Kuzumochi [久寿餅] is not to be confused with its homonym [葛餅], a similar sweet made from kudzu arrowroot starch.)
For my first taste of the fabled confection I chose the Sumiyoshi manufacturer and café close to the main gate of Kawasaki Daishi temple. The shop is practically on hallowed ground, open-fronted and undeniably welcoming.
Kuzumochi, it turns out, has a blancmange-like texture and, by itself, almost no discernible flavor. Connoisseurs of the local sweet however say they can identify subtle differences in hue, flavor and texture between the numerous brands. This can only be the result of a variance in the fermentation period of the wheat starch or in the preferred manner of its steaming. Combined with the traditional toppings of kuromitsu molasses and kinako roasted soybean powder, kuzumochi is a pleasingly rustic, old-fashioned sort of sweet, low on calories but surprisingly filling. Since the lactic acid bacteria present in the fermentation process is a proven probiotic, kuzumochi is said to work wonders on one’s intestinal flora, too.
On leaving Sumiyoshi, the sound of a drum had me quickening my stride in the direction of the temple’s Main Hall. A ceremony was under way. I took off my shoes and sat with a congregation of about twenty visitors dotted about the wide, tatami mat-covered floor. In front of us, a row of colorfully clad priests was chanting behind another priest feeding a sizable fire at the foot of the altar. The temple offers this gomakitou ceremony multiple times every day, to “burn up worldly desire, the source of suffering.”
On my return to the station, back down the narrow street lined with shops selling auspicious goods of various kinds, I succumbed to desire at the last and bought a bag of the Matsuya sweet shop’s famous cough drops. This tontoko rock candy maker has been in business since the first year of modern times in Japan, 1868, and while I left the sticky hard tontoko for those with more confidence in their teeth, I can vouch for the herbal cough drops, which are mildly gingery and honey sweet.
There is mileage in Ogura’s “Fermentation Nippon Tourism” concept, that is for sure.
This article first appeared in the September/October issue of the Japan Journal.