Life With Soy Sauce: Discovering the Infinite Possibilities of Soy Sauce With Craftsmen at a Specialty Shop

“Shoyu” (soy sauce) is a seasoning that has been commonly used in Japanese cuisine since ancient times. Made by fermenting soybeans, soy sauce’s flavor becomes deeper and more complex as it is brewed over time. Also beneficial for one's health, it is an essential ingredient in Japanese food culture and cuisine. Soy sauce can be categorized by its brewing method, color, and salt content, and similar to wine, is further divided by cooking method and dish. For this edition of our "Culture of Japan" series, we visited "Shokunin Shoyu," a soy sauce specialty shop in Ginza, Tokyo and spoke with a soy sauce expert to learn more about the appeal of this traditional seasoning.


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What Is Soy Sauce?

Soy sauce, with its unique aroma and flavor derived from fermented soybeans, is a staple of Japanese cuisine. It can be found in various dishes at restaurants and home dining tables throughout Japan, such as grilled or simmered dishes, salads, pickles, soups, or as a simple dressing.

There are three essential ingredients for soy sauce: soybeans, wheat, and salt. According to the Japanese Agricultural Standards (JAS), soy sauce must be made using soybeans, and any product that does not contain soybeans cannot be labeled as soy sauce.

The traditional process of making soy sauce widely used today was established during the Edo period (1603-1868). The process involves steaming soybeans, roasting wheat, mixing them together and adding “tane-koji” (fermentation starter), and cultivating the soy sauce koji mold. Next, salt water is added to turn it into what is called "moromi," a paste-like substance that ferments before separating into liquid soy sauce and solid soy sauce lees. Finally, the moromi is fermented, aged, pressed, heated, and bottled to become fresh, fragrant soy sauce.

Soy sauce is fermented in plastic, iron, or wooden tanks. In addition to the main ingredients, some soy sauce products may add legally permissible food additives such as rice, sweeteners, and flavoring agents to adjust the flavor during manufacturing according to consumer preferences. For example, in Kyushu, Japan, sweet soy sauce is preferred, so hydrolyzed vegetable proteins (extracted from corn and soybeans that enhance umami flavor) are often added to the raw soy sauce and blended to create a unique flavor.

The first appearance of the word "shoyu" (soy sauce) in Japanese literature was in the daily vocabulary dictionary " Ekirinbon Setsuyoshu," which was published in 1597 during the Azuchi-Momoyama period. At that time, soy sauce was described as "miso no abura” (miso oil).

The origin of Japanese soy sauce has not been entirely determined, but it is generally believed that the production of miso, the prototype of soy sauce, was introduced to Japan from ancient China. At that time, the character for “sho” in “shoyu” referred to fermented foods divided into three categories: fish or meat-based (“uobishio” and “shishibishio” respectively), herb-based made from salted vegetables (“kusabishio”), and grain sauce made from salted grains (“kokubishio”). Kokubishio is said to be the prototype of modern soy sauce and miso, but there is also a theory that the delicious liquid that collects at the bottom of a miso barrel could be the ancestor of soy sauce.

At first, soy sauce gained popularity in the western region of Japan. As the population grew and Edo (modern-day Tokyo) developed, the quality of soy sauce produced in the Kanto region, specifically around Chiba Prefecture, improved steadily, leading to a gradual shift in the center of soy sauce production towards Edo. To cater to the tastes of the people in Edo, a richer, dark soy sauce was developed during this time. According to the Family Income and Expenditure Survey conducted by the Statistics Bureau of the Ministry of Internal Affairs and Communications, per capita annual soy sauce consumption has been decreasing. However, soy sauce still remains an essential seasoning and core ingredient in Japanese cuisine.

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The Benefits of Soy Sauce, One of Japan’s Beloved Fermented Foods

Soy sauce, a versatile condiment made mainly from soybeans, is a fermented food with many uses. Its components, such as amino acids, vitamins, and minerals, are produced through the fermentation process of koji. These components add delicate texture and savory flavor and offer numerous health benefits. For example, soy sauce is rich in probiotics, such as lactic acid bacteria, which have been found to improve gut health and boost immunity in recent studies. Additionally, the fragrance component called "furanone," which is developed during the soy sauce brewing process, has antioxidant properties.

Overall, it can be said that soy sauce made from high-quality ingredients with simple components is beneficial to the body. However, soy sauce is high in sodium, so excessive consumption can burden the body. Therefore, people who need to monitor their salt intake in particular should be careful about their consumption and consider choosing types of soy sauce with reduced sodium. In the following sections, we will introduce different types of soy sauce classified by salt concentration and color.

Types, Characteristics, and Production Regions of Japanese Soy Sauce

The common perception of soy sauce is just something of dark color and a strong fermented flavor of soybeans, but in reality, there are many types of soy sauce, which are divided into detailed classifications. Due to an increased focus on health, low-sodium soy sauce that reduces salt while maintaining flavor and aroma has recently gained popularity. The Japanese Agricultural Standards classify soy sauce into the following five categories based on characteristics such as nitrogen content (an indicator of umami flavor) and color intensity.

Tamari Shoyu

Tamari shoyu is made primarily from soybeans and is brewed with a small amount of water to intensify its flavor. As a result, it has the most prolonged aging period among all soy sauces, resulting in a deep color, thick texture, and rich aroma. Tamari shoyu is mainly produced in Aichi, Gifu, and Mie Prefectures in the Chubu region of Japan, particularly in the town of Taketoyo in Aichi Prefecture.

Most soy sauce breweries take two to three years to prepare it. The umami flavor of tamari shoyu is the highest among all soy sauces, making it a versatile seasoning that can be used directly, as a cooking ingredient, or as a dipping sauce for dishes such as grilled fish.

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Saishikomi Shoyu

Saishikomi shoyu (refermented soy sauce) is a soy sauce brewed twice using soy sauce instead of salt water during the second fermentation, hence its name. Compared to regular dark soy sauce, it requires double the amount of ingredients and manufacturing time, resulting in a longer aging process, a thick texture, and rich umami and mellowness.

Nevertheless, it has a well-balanced flavor and aroma and is perfect for serving with red-fleshed sashimi (like tuna) or enriching curry or steaks. Although it originated in Yanai City, Yamaguchi Prefecture, breweries all over Japan now produce the sauce.

Koikuchi Shoyu

Fresh koikuchi shoyu (dark soy sauce) has a beautiful reddish-brown color and is widely used both as a dipping sauce and for cooking. It is produced throughout Japan, from Hokkaido to Okinawa, and is the most commonly used and versatile type of soy sauce. As a matter of fact, it accounts for 80% of the soy sauce market in eastern Japan.

The production method of dark soy sauce was established during the Edo period. Originally, tamari shoyu was the principal variant produced, requiring only soybeans in its recipe. However, later on, wheat was added to the recipe. With a 1:1 ratio of soybeans to wheat, dark soy sauce undergoes a transformation where the soybean proteins become umami components, and the wheat starch becomes a fragrance component.

The aging period varies depending on the brand, ranging from about six months to two years, and the brewing process requires considerable effort, including the need to stir the mixture periodically. It is a versatile seasoning that matches well with tofu as well as being used as a dipping sauce.

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Usukuchi Shoyu

You may see usukuchi shoyu often in Western Japan. Although light in color, it is actually high in sodium.

Generally, soy sauce becomes darker in color with more extended aging periods, increased exposure to air, and higher temperatures. Conversely, shorter aging periods, lower temperatures, and fewer times being stirred result in lighter colors. Usukuchi shoyu is similar to koikuchi shoyu in the production process, but it is made to prevent the color from getting too dark. Some manufacturers add rice koji to reduce the saltiness.

Usukuchi shoyu is suitable for dishes where you don't want the soy sauce color to show, such as stews, soups, and “tamagoyaki” (Japanese omelet). It can also be used as a replacement for salt. In regions where usukuchi shoyu is commonly used, many households use both usukuchi and koikuchi shoyu in the kitchen.

Shiro Shoyu

Shiro shoyu (white soy sauce) is a light, amber-colored soy sauce with a lighter color than even usukuchi shoyu. While regular soy sauce is typically made with equal amounts of soybeans and wheat, white soy sauce is made mainly with wheat and a small amount of soybeans. It has a sweet and fragrant taste and a short aging period, which results in a high salt content and subdued umami flavor, allowing the natural taste of the ingredients to shine through.

In Japan, only a few manufacturers specialize in shiro shoyu, with the majority located in the city of Hekinan in Aichi Prefecture. In Japanese cuisine, soy sauce is often used for simmering ingredients, but shiro shoyu is suitable for dishes with a lighter color, such as soups and “chawanmushi” (savory egg custard), as it doesn't darken the food and brings out the flavor of the ingredients. It can also be used in salad dressings along with olive oil.

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Shokunin Shoyu Matsuya Ginza: Specialty Shop for 100 ml Bottles of Soy Sauce

Although soy sauce may appear to be a commonplace seasoning, it holds a rich history and cultural significance in Japan. To learn more about the world of Japanese soy sauce, I visited "Shokunin Shoyu," a soy sauce specialty shop in Tokyo's Ginza district.

"Shokunin Shoyu" is a specialty shop mainly selling 100 ml bottles of soy sauce. During his travels throughout Japan, the shop's founder, Mantaro Takahashi, witnessed the struggle of skilled artisans who pour their hearts and souls into crafting traditional and regional soy sauces yet struggle to compete in the mass-produced market. Determined to make a difference, he devoted himself to bridging the gap between the buyers and the makers of artisanal soy sauces.

According to Takahashi, just as every region of Japan has its own local traditional and original food, he thinks the same goes for soy sauce. In an effort to spread the appeal of soy sauce to a broader audience, Takahashi visited more than 400 soy sauce breweries throughout Japan. He went on to establish "Shokunin Shoyu" with the aim of selling traditional soy sauces produced by these breweries, which are imbued with the unique characteristics of their respective regions and brewers. Despite this, the large bottles that the soy sauces were packaged in were not in line with people's current way of life. As a solution, he decided to switch to standardized 100 ml bottles for sale.

Around the same time, he launched the online shop "Shokunin Shoyu," opened a direct management store in his hometown of Maebashi, Gunma, and in 2016, set up another branch in Matsuya Ginza in Tokyo which is an area frequented by foreign tourists. He aims to connect soy sauce producers with buyers, acting as a liaison between the two.

I visited Shokunin Shokyu in Matsuya Ginza on a weekday morning. In the food section on the second basement floor, I was greeted by a display that felt as though it belonged in a miniature-sized museum: identically sized glass bottles held various soy sauces of different colors, each decorated with its own beautiful label. The store manager, Mori, kindly assisted me and courteously answered my questions.

Firstly, "Shokunin Shoyu" adds one original category of soy sauce, "amakuchi shoyu," to the five categories established by the Japanese Agricultural Standards mentioned earlier: tamari shoyu, saishikomi shoyu, koikuchi shoyu, usukuchi shoyu, and shiro shoyu. "Amakuchi shoyu" is a sweet soy sauce commonly used in coastal areas such as Kyushu and Hokuriku, and its sweetness varies depending on the region. It is particularly suitable for grilled onigiri, rice with raw egg, and white fish sashimi.

As shown in the diagram above, each soy sauce is arranged based on the length of the aging period, the concentration of the soy sauce's flavor, and its compatibility with different ingredients. Starting from the left, the shiro shoyu, which has a six-month aging period, is used to bring out the ingredients' natural flavors. The aging period and the characteristics of the soy sauce increase from left to right. Tamari shoyu, which has the most prolonged aging period of three years and is rich in umami, is located on the far right.

Mori, the manager of the Matsuya Ginza store, joked that he did not like soy sauce before he started working at "Shokunin Shoyu." However, he became aware of the diversity of soy sauce after joining the company and now holds 15 to 20 different types of soy sauce at home.

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How To Choose Soy Sauce

Soy sauce is a seasoning made by microbial fermentation, and compared to other brewed products, many elements can be adjusted, so soy sauce in different regions varies slightly depending on the habits and preferences of the locals. Like wine, soy sauce produced by distinct areas and people has its own personality and uniqueness. For example, soy sauce from a meticulous brewer has a delicate and calm texture, while soy sauce from an unconventional and passionate brewer sparks with energy.

Bear in mind that this applies to both the craftsman and the customer consuming it. If the person who eats it is different, or if the environment in which they eat is different, their definition and idea of what constitutes deliciousness may vary slightly. For example, even when eating the same sashimi, there are soy sauces that pair well with red meat fish and others that pair well with white fish, so there is no universal method on how to choose the best soy sauce.

When asked how a beginner should buy soy sauce, Mori replied: "One of the major characteristics of soy sauce is that it can be divided into various types depending on its use, such as for dipping, pouring, or cooking. Therefore, the first step is determining which type you want to use, whether it's for marinating, enriching your dishes, or both. Then, I recommend asking the staff at a ‘Shokunin Shoyu’ store to suggest a soy sauce that suits your desired taste.”

If you're unsure how to use it, the cute illustrations of dishes and food on the paper packaging of “Shoyu Shokunin” and the recommendations by staff, such as Mantaro Takahashi and Mori, can be helpful references. These can guide you to intuitively understand the appropriate way of using each type of soy sauce.

Although it was a weekday, many customers stopped by the shop while I was there. According to Mori, many Japanese customers purchase Tamari soy sauce to go with sukiyaki, special soy sauce to add to kelp or bonito flake stock or raw egg rice, as well as saishikomi shoyu or usukuchi shoyu to use with red and white fish. There are also customers from Kyushu who order amakuchi shoyu. While the store used to receive many tourists from Asia and Europe before the pandemic, on the day of the interview, I saw a Western customer ordering two types of "Yamaroku" soy sauce from Shodoshima in Kagawa Prefecture.

Shokunin Shoyu's Recommended Soy Sauce and How to Use It

On the day of the interview, Mori recommended three types of soy sauce (from left to right):

  • Usumurasaki: a low sodium usukuchi shoyu by Suehiro Shoyu, a long-established brewer in Hyogo Prefecture. It uses plenty of rice koji in its production process to create the typical mellow flavor of usukuchi shoyu. Its color and aroma are just right, and it is suitable for pouring over dishes to bring out the original flavors of the ingredients. Its delicate flavor makes it ideal for foods such as silken tofu, white fish like sea bream and flounder, and sashimi like scallops and sweet shrimp. It can also be used to enhance the flavor of meat and dumplings.
  • Heiemon: a koikuchi shoyu by Suzuki Shoyu Ten in Fukushima Prefecture. It is brewed in natural wooden barrels and made entirely by hand (the wooden barrels used to steam the soybeans are homemade too). It has a delicate fragrance and a mild sweetness, so first pouring a bit of it on piping hot white rice is recommended.
  • San-nen Jukusei Shoyu: a saishikomi shoyu by Morita Shoyu in Okuizumo, a heavily snowy area in Shimane Prefecture. The company is committed to the quality of raw materials to ensure that people of all ages can enjoy it. It has a rich and deep umami flavor distinctive of saishikomi shoyu and a refreshing aftertaste. It is good for adding richness and umami flavor to stir-fry dishes, and using it in soba dipping sauces helps bring out its deep aroma.

In recent years, “toumei shoyu" (clear soy sauce) has become a hot topic, overturning the preconceived notion that soy sauce is synonymous with black. A new genre of soy sauce started by Fundodai in Kumamoto Prefecture is also available at Shokunin Shoyu. It mainly has a koikuchi shoyu base, and through the distillation process, it retains the flavor of brewed soy sauce while removing the typical dark tones. Being clear, it can be used in both Japanese and Western cuisine as a versatile seasoning without changing the appearance of the dishes.

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Author's Favorites

I was interested in trying out the saishikomi and shiro shoyu, so I asked Mori for his recommendations and ended up purchasing the two bottles in the picture above. The first one (on the left) is an organic JAS-certified shiro shoyu made by Shichifuku Brewery in Aichi Prefecture. Unlike soy sauce made by using pressers to extract the juices, this sauce is produced through natural extraction, resulting in a refined sweetness and elegant saltiness that will make you keep reaching for it. The other one is the San-nen Jukusei Soy Sauce (on the right), which had the deep and complex flavor I was looking for with an amazingly refreshing aftertaste! I tried pairing them with dishes such as firm tofu, red fish sashimi, and fried foods, and found that they all matched perfectly.

Soy Sauce: An Integral Part of Japanese Cuisine

Using only simple ingredients such as soybeans, wheat, salt, and koji, soy sauce has been an indispensable part of Japanese food culture since ancient times and has been refined and condensed for centuries. However, the possibilities for using soy sauce go far beyond that – getting to visit "Shokunin Shoyu" showed that the potential pairings of soy sauce and different foods go far beyond imagination. The next time you visit Japan, consider stopping by "Shokunin Shoyu" to find the perfect soy sauce you may have always been waiting for.


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Kanto Feature

The information in this article is accurate at the time of publication.

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About the author

Fuchi Pan
Tokyo based Taiwanese writer/ editor. Passionate about Japanese food culture, culinary traditions and local/seasonal quality ingredients.
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