Soy sauce

Aichi's specialties of tamari and white soy sauce

To make soy sauce, koji mold is grown on the raw ingredients of soybeans and wheat, added to salt water, and left to ferment with the resulting liquid the goal of the process. Soy sauce comes in five varieties, in the order of color depth: Tamari, saishikomi (refermented), koikuchi (the more typical type), usukuchi (a lighter type), and white soy sauce. All five are brewed in Aichi Prefecture with tamari soy sauce and white soy sauce being its specialties.

Tamari soy sauce has a thicker body and robust flavor which goes great with sashimi and other types of sushi. It is found in local, traditional specialty hitsumabushi, or eel resting on a bed of rice, as well as ramens and soups in the southern Chita region. The richness of tamari soy sauce is said to have come about after collecting the liquid which collected during the process of bean miso production, resulting in its deep umami and aromatic scent. Contrary to what one might think when looking at its deep color, it has less sodium than koikuchi and usukuchi soy sauces. With a larger number of soybeans to wheat, some tamari soy sauces are made without the need for wheat, making them gluten-free.
On the other end of the spectrum is white soy sauce. While not actually white but a lighter amber color, white soy sauce offers its own particular flavor profile. It is said to have been born at the end of the Edo period (1603–1868) in present-day Hekinan City, and the sauce's production still continues there today as well as in the greater Mikawa region. With a lighter color, it is often used in soups; chawanmushi, or egg custard steamed in a teacup; rolled omelets; and other tantalizing treats.

A trip to Nakasada Shop in Taketoyo, town of tamari soy sauce, continuing traditional natural fermentation in vats 2.55 meters deep

The town of Taketoyo is located almost right in the middle of Chita Peninsula. The area's warm climate and quality water are ideal for fermentation to occur, and its brewing industry blossomed in the Meiji period (1868–1912) with the introduction of railways and ports. Taketoyo Town is known as the "Town of Miso and Tamari Soy Sauce" and is home to five factories using olden-time wooden vats for natural brewing. We took a trip out to one of them, the long-standing Nakasada Shop since 1879, for a factory tour (reservations required).

A lesson in the brewing industry's evolution and history at a national tangible cultural property: the Brewing Tradition Museum

The first stop on our journey into Taketoyo's brewing culture was the Brewing Tradition Museum. It still utilizes the salt storehouse built in 1916 and designated a national tangible cultural property. Inside the museum are a variety of materials describing Nakasada Shop's history and Taketoyo's brewing culture as well as illustrated panels and more portraying the brewing industry's evolution. Once you understand the brewing process, it's easy to see how the invention of tamari soy sauce unfolded from the bean miso production process.
Antique tools used in brewing are also on display, available for you to touch and operate.

Illustrations paint a picture of the process from which miso is created
Guessing tools' uses

Giant vats full of delectable bacteria and tamari soy sauce's distinct and impressive circulation technique

Next was to the aging factory where tamari soy sauce is actually made. Step through the doors, and you're greeted by lines of enormous cedar vats standing 2.55 meters tall! These vats are a size bigger than the typical ones used at Taketoyo's other factories and the number still in use is apparently pretty rare throughout Japan.
The raw ingredients used in tamari soy sauce are Japanese soybeans and sun-dried salt, and all sorts of different bacteria living around the factory and in the vats go to work fermenting the batch for three years. The bacteria become workaholics during the summer while taking it easy during winter hibernation, so the brewers have to help the bacteria along by season during the tamari soy sauce's production.
At one time Nakasada Shop scooped out and sold the tamari soy sauce which pooled up at the bottom of the vat during bean miso production, but now brews them separately to ensure the tastiest flavor in each. Tamari soy sauce has an interesting production process miso doesn't though: recirculation. Brewers scoop up the tamari sauce at the bottom with a ladle, bringing it up to the top and pouring it over the surface in a magical scene. It also helps to create a more uniform degree of aging and introduce the tamari sauce into the koji more thoroughly, bringing out the sauce's umami.

Black walled buildings all around the premises offer a look into the Japanese townscape of yesteryear

Mr. Yasunori Nakagawa, sixth-generation brewer, recirculating the sauce. The tamari sauce rises up above the stone weights during the summer.
Giant vats rise some 2.55 meters into the air, holding around 13 tons of miso. (Bouffant caps required for the tour. Excluded here for photographic purposes.)

Try the different flavors in a taste test and check out the precious fresh, naturally pooling tamari soy sauce!

At Hongura, the company-owned shop, you can peruse and purchase the pride of Nakasada Shop, tamari soy sauce; miso; koji; amazake sweet, low- or non-alcoholic sake; and other products. Of course, the taste and strength of umami differ in tamari soy sauces depending on the amount of water used, so there are a number of different flavors. Feel free to ask staff for tastings.
One we definitely recommend tasting is Genzo Hozan Tamari Soy Sauce. This product is the tamari soy sauce that naturally pools up during the miso production process, and while born in an approximately 2-meter-deep vat, the amount is miniscule, making it a precious soy sauce variety. Enjoy the distinct flavors of rich yet mellow umami from whole Japanese-grown soybeans.

If you're not sure which to go with, the three-variety small bottle soy sauce pack is a sure bet
A burst of umami to your cooking with just a dash of Genzo Hozan Tamari Soy Sauce

Miso and tamari soy sauce Brewing Tradition Museum; Nakasada Shop, General Partnership details page (Japanese)

Hekinan City's producer of rare white soy sauce Yamashin, Inc. and the mystery of the sauce's light color

Hekinan City is the birthplace of white soy sauce. And one of its residents, Yamashin, Inc., has been producing the sauce for 200 years. It even received the Minister of Agriculture, Forestry and Fisheries Award for the second time at the 2024 National Soy Sauce Competition! White soy sauce is used as a condiment by professional chefs as well as a raw ingredient in processed foods, and in recent years, is gaining popularity abroad as its avenues of use expand. Its greatest characteristic is probably the light color and the ability to bring out the inherent flavors of the foods with which it is used. So, how does such an uncharacteristically light and transparent soy sauce come about?

Nine parts wheat and one part soybeans for a clear, sweet soy sauce

Hekinan City lies along the Mikawa Bay of southern Aichi and has prospered since antiquity thanks to its brewing industry. According to Yamashin, Inc.'s records, white soy sauce may have begun when brewery workers in the city took the transparent upper layer occurring in Kinzanji Miso—a variety of miso eaten as is together with other foods—as a hint on how to create a new, lighter soy sauce.
White soy sauce is so rare that it makes up but one percent of the total soy sauce production around Japan. Tour Yamashin, Inc.'s factory after making a reservation for the incredible sight of wooden vats containing the fermenting sauce just as you would have seen eons ago. And while normal soy sauce uses soybeans as its main ingredient with minimal wheat, white soy sauce is the opposite with the amount of wheat greatly outweighing soybeans. It is prepared twice so as not to make contact with the air and gently aged in the vats for half a year before finishing as a light-colored, sweet soy sauce.

Sauce is stored in tanks with little affect to the taste as well as wooden vats. (Bouffant caps required for the tour. Excluded here for photographic purposes.)
White soy sauce's light color is one of its characteristics, bottled without pasteurization to retain its amber hue

You don't have to enjoy white soy sauce at high-end restaurants—There's no place like home!

When most think of white soy sauce, they envision expensive Japanese restaurants, but in Aichi exists a culture of culinary use at home. It is also a must in Hekinan City rice porridge. White soy sauce has a much less salty taste than regular soy sauce and its light color lets the colors of other ingredients to shine through. This allows its easy incorporation into Western and Chinese foods as well as Japanese, leading to more and more shipments abroad.
At Yamashin, Inc.'s reception office at the entrance, a variety of different products are available for purchase. Shop for the perfect versatile condiment, such as the brewery's trademark product Yamashin White Soy Sauce (Special Grade) prepared in traditional wooden vats or its White Soy Sauce Soup Stock made from white soy sauce, dried bonito flakes, dried mackerel flakes, dried sardines, shiitake mushrooms, and kelp. Keep a little of Aichi at your kitchen table and as a helper in the kitchen with savory white soy sauce!

Yamashin, Inc. is hard to miss with its tasteful sign and retro mailbox

Yamashin White Soy Sauce (Special Grade), winner of the highest award at the 2024 National Soy Sauce Competition
The entire premises are home to a refined atmosphere with each building performing its own task from koji mold production to bottling