An old method soy sauce, which takes double the time and ingredients to make compared to a typical soy sauce found today.
The Japanese word "shoyu" first appeared in writing during the Azuchi-Momoyama period, but a relative of soy sauce existed even earlier. This was called "hishio" and was made with preserved ingredients such as fish intestines, vegetables, and rice in salt that were fermented. Nobles used Hishio as a condiment during the Asuka period. The term "hishio" could also be found in songs contained in the Manyoshu, the oldest existing collection of Japanese poetry.
During the Kamakura period, the Zen monk Kakushin, who founded Kokokuji Temple in Kishu Yura (modern-day Hidaka District, Wakayama Prefecture) brought back the Kinzanji method of making miso paste from China in the year Kencho 6 (1254).
There is a theory that soy sauce was first discovered when Kakushin noticed how delicious the broth was that accumulated at the bottom of the miso vat, but this remains folklore that was passed down through generations. By the Muromachi period, soy sauce was created using wheat and malted rice, and gradually spread to the people in surrounding regions.
By the Edo period, soy sauce began to be produced on an industrial scale and spread throughout the country. The manufacturing method of soy sauce reached the Kanto region through word of mouth by people who emigrated from the villages nearby Yuasa, where soy sauce production flourished, to Boso-hanto, a peninsula that encompasses the entirety of Chiba Prefecture. There, soy sauce production continued to thrive in cities such as Noda and Choshi in response to the growing demands in the capital city of Edo, which was experiencing a huge increase in population.
Like the soy sauce that was originally produced in Yuasa, the soy sauce in the Kanto region, commonly referred to as "koikuchi-shoyu", had a dark color and strong taste. However, during the mid-17th century, a new type of soy sauce referred to as "usukuchi-shoyu" that was lighter in color and contained less salt was developed in the Banshu (modern-day Hyogo Prefecture) and Tatsuno by shortening the ageing period to reduce the fermentation process. This is one of the roots to the differences in the preference of taste between the soy sauce from the Kanto region (Edo) and the Kansai region (Kamigata).
In addition to koikuchi-shoyu and usukuchi-shoyu, there is "tamari-shoyu", which is produced using almost only soybeans and "shiro-shoyu", which is produced using almost only wheat, both which are primarily produced in the Tokai region. There is also "kanro-shoyu", which originated in Suonokuni (modern-day eastern part of Yamaguchi Prefecture) and Yanai during the Tenmei era (1780s).
Kanro-shoyu is also referred to as "twice-processed soy sauce", and as the name implies, it is produced by taking standard soy sauce and putting it through a double fermentation process. It has a thick and sweet taste, originating from Yanai and spread throughout the Nishi-Chugoku and northern Kyushu regions.
"Sagawa Shoyu" from Yanai, Yamaguchi Prefecture was established in 1830 and is one of two remaining soy sauce breweries that still produce kanro-shoyu in this region today. A row of merchant houses, with white walls and latticed windows, that span over 200 meters and were built during the Muromachi period have been preserved in the Furuichi Kanaya district.
This area was once the center of commerce of the port city of Yanai, and it also served as a strategic position for the Inland Sea area dating back from the Middle Ages. Inside the gigantic Sagawa Shoyu brewery, which is located near the premises, craftsmen continue to produce kanro-shoyu in Yoshino cedar vats that were built in Meiji 4 (1871) and have a capacity of approximately 5,400 liters using traditional manufacturing methods that have been passed down through generations.
Denbe (the fourth) of the Takada family developed the brewing method of kanro-shoyu, and after offering it to his lord (Iwakuni Domain) Yoshikawa-ko during the Tenmei era (1781-89), it was praised for its sweet flavor (kanro), which is also how it got its name.
The manufacturing procedure of kanro-shoyu is as follows.
1: Steam soybeans, combine it with ground wheat inside a boiler, add seed malt, and spend approximately 30 hours to create malted rice.
2: Pour approximately two tons of malted rice along with salt water into a cedar vat, and age it for approximately one and a half years while experienced craftsmen stir it at the right timing.
3: Press the raw unrefined soy sauce using a compressor (unstrained soft solids that have been pre-fermented), and add new malted rice to the removed koikuchi-shoyu, and age it for another one and a half to two years.
4: Press the double-aged unrefined soy sauce, add seasoning, and bottle it up.
The entire process of manufacturing kanro-shoyu generally takes up to three to four years, which is approximately twice the length of time required to produce regular soy sauce, and a large amount of raw ingredients and effort. The color of kanro-shoyu is thicker than koikuchi-shoyu, has a strong umami flavor (from the amino acids that are produced after the soybean protein is decomposed), and contains less salt content.
The glossy jet-black color, sweet and rich aroma, and rich flavor of the kanro-shoyu perfectly compliment dishes such as sashimi, chilled tofu, and sushi. Even today, it is widely regarded as the highest quality soy sauce.
A portion of the soy sauce brewery, which was relocated during the Meiji period, has been opened to the public as a museum where various traditional soy sauce manufacturing tools that have been used for generations are put out on display. The pots lined up along the shelves on the walls are actual containers that were once used when selling the soy sauce. In the past, people who used up their soy sauce would recycle the pots by returning it to the store and have them refilled with however much soy sauce they want to purchase.
Traces of traditional Japanese food culture that have been passed down through generations are carved into each of these appliances. Kanro-shoyu, which has a full-flavored mellow taste, characteristics shared by vintage wine, serves as a historical testimony of the lives of the people of Yanai that continues to be passed down to today's generation.
SAGAWA SHOYU STORE (Yanai Kanro-shoyu Culture Museum)
3708-1 YANAI, YANAI CITY, YAMAGUCHI 742-0021
0820 22 1830
Opening Hours: 8:00-17:00 (Monday-Saturday), 9:30-16:30 (Sunday, Holiday)
Closed: New Year's holiday
Survey, defined as: to examine or inspect. In these features, we will be reporting on things, people, places, or cultures that inspire us in our daily work of making products.
edit & text: Kosuke Ide
photo: Keisuke Fukamizu