KOZAKI, Japan - A small community near Tokyo, one of the traditional homes to myriad brewed products such as sake and soy sauce, is doing its best to ride the recent wave of interest in fermented foods to make its name.

The "fermentation town" of Kozaki in Chiba Prefecture, approximately 60 kilometers east of Tokyo, has hosted annual festivals each March since 2009 featuring its sake breweries, and opened a flagship fermentation store in 2015 to spread the word about the health benefits of fermented foods, hopefully boosting tourism along the way.

The facility, a roadside rest stop, sells some 500 different fermented foods from across Japan, including miso, fish sauce, dairy products and tea, and offers lessons to promote the "culture of fermentation."

Fermented foods are produced or preserved through the activity of microorganisms, with the processes usually involving yeast or bacteria, often allowing products to be kept for a long time. Fermented foodstuffs and beverages are said to improve digestion and enhance the immune system.

The most prominent and popular Japanese fermented foods include "natto" sticky soybeans and "tsukemono" pickled vegetables, while "kimchi" Korean pickled vegetables and "sauerkraut" German fermented raw cabbage are well-known examples from other cultures.

Kozaki, with its population of some 6,500, once flourished with its sake and soy sauce breweries taking advantage of locally produced rice and soybeans and its proximity to the Tone River, through which goods were carried to Edo, as current-day Tokyo was known.

In the Edo and Meiji periods from the 17th to the early 20th centuries, the river transportation route had an advantage because it was much faster than conventional trails traveled by foot.

With the development of roads, however, the town lost its edge and competition with other areas intensified, resulting in the disappearance of many local producers. Only a handful of larger businesses survived, according to Kozaki town officials.

In a bid to revitalize the town, the municipality made an effort to rediscover its history and opened an office in May dedicated to the promotion of fermentation's features.

"It's now been almost 10 years since we started," Yoshito Ikegami, head of the newly created town department, said of the local sake festivals. "We're grateful that people are paying attention." The latest event this March drew some 55,000 visitors.

The lessons offered at the facility are called "Puku Puku" courses, an onomatopoeic reference to the bubbling fermentation process. They vary from how to make your own mozzarella cheese to dyeing cloths with indigo, which also involves fermentation methods.

According to Ikegami, to create the dye the dried leaves of the indigo plant are combined with water, and sometimes sake, which then undergo a process of natural fermentation.

(Illustrated flyers inform locals and visitors of bimonthly fermentation courses at the rest stop.)

"We wanted to provide courses for people to be able to create and experience fermented foods at their own homes, instead of just purchasing the goods," said Satomi Sawada, a colleague of Ikegami.

Born and raised in Kozaki, Sawada, helps organize the classes and is an expert in fermented goods herself. Her grandmother was an indigo dyer, whose house had pots to dye the threads and rooms that were used to weave the threads, she says.

"Fermentation is quite similar to human society," Sawada said. "You need a whole range of microorganisms to support and collaborate in order for the process to work."

The town office invites experts from around the country to offer lessons on topics that also include cooking of miso, soy sauce, "umeboshi" Japanese salted plum and kimchi.

In one class held in July, participants learned how to make their own "nukazuke," a Japanese preserved food made by fermenting vegetables in a bed of "nuka" rice bran.

At the beginning of the lesson, participants were each handed a plastic bag of the fermented rice bran, in which cucumbers, avocados, radishes, tomatoes and carrots, as well as the more unusual ingredients -- boiled eggs and fruits -- were buried to ferment.

The organizers then provided ready-made nukazuke pickles for the day's students to taste, alongside other fermented foods such as miso soup and bonito flakes, to enjoy and learn about the vast range of possibilities.

According to that day's specialist, Hajime Yanai, president of a company specializing in health food products, the fermented rice bran offers health benefits for its abundance in vitamin B1 and natural fibers.

With its generous amount of plant-based lactic acid bacteria, nukazuke pickles are also beneficial for gut flora, increasing immunity and also improving blood circulation, according to Yanai and Sawada.

The town of Kozaki is also home to a time-honored soy sauce maker Fujihan Shoyu, which was founded in 1877.

The company's brewery has been officially certified by the government as a part of Japan's industrial modernization heritage with much of the equipment left in its original state from the time of founding, despite the soy sauce-making method being much modernized now, according to its owner and president Hanji Takahashi.

The single-story facility retains its traditional Japanese architecture and in the back are several large more than 100-year-old wooden barrels that can store approximately 3,000 liters of the soy sauce, although they are no longer in use.

"Local residents have a personal attachment to a certain type of soy sauce because the taste differs depending on the region and brewer," he says.

Although Chiba Prefecture is the largest manufacturer of the condiment in Japan, many local soy sauce makers have gone out of business due to the monopoly of leading brands, Takahashi said.

Fujihan Shoyu temporarily stopped brewing soy sauce using its original facilities 40 years ago due to the aging Meiji-era building and machinery, as well as difficulty in securing investment and shortage in labor.

(Satomi Sawada)

The company, however, has been working on reviving the Fujihan brand over the past four years using locally sourced ingredients and Edo-period processing methods as opposed to modern techniques, in hopes of starting the traditional soy sauce making again within the next couple of years.

"People have come to feel traditionally made soy sauce is more reassuring and safer in recent years," he says.

Takahashi also regularly holds homemade soy sauce lessons at the Puku Puku courses, as well as in Kashiwa, Chiba Prefecture, where participants can make sauce using plastic bottles.

In one class held in July, the sixth-generation soy sauce maker explained to his students about the significance of soy sauce in Chiba, which supplies the most soy sauce in Japan.

He then provided the main ingredients -- soy beans, wheat, water and salt -- explaining how the fermentation process can last from months to years.

The powdered soy beans, wheat and the yeast were first poured into a 1-liter plastic bottle, after which the students slowly decanted salt water into the mixture.

(Soy sauce brewer Hanji Takahashi poses for a photo with students during his homemade soy sauce class.)

According to Takahashi, the water must have a 22 percent solution of salt -- if any higher, the fermentation process stalls, while unwanted bacteria can contaminate the condiment if it's any lower.

The bottles are then shaken at least 30 times to ensure all ingredients are thoroughly mixed. They will have to be shaken every day for another week and kept in a refrigerator to ensure the process of fermentation continues in a cool environment.

Students have to wait at least until next spring to taste their homemade soy sauce.

"I would like to lead a healthier life (eating) fermented foods," said Erika Watanabe, a 35-year-old mother at the soy sauce class held in Kashiwa. "I want to learn more, and hope the people around me learn about its benefits as well."

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