Savoring Japanese Soy Sauce
“A Conversation With Keiko Kuroshima, Soy Sauce Sommelier”
Japanese soy sauce, distinct from other types of soy sauce found in Asia that are quite different in flavor, is the cornerstone of Japan’s light, clean-tasting yet deeply satisfying cuisine. As an expression of umami savoriness, it holds irreplaceable roles as a seasoning in cooking and a condiment at the table, by adding depth, complexity, and an exquisite touch of flavor to culinary creations. Remarkably versatile, it has the ability to enhance the flavors of any cuisine, thanks to its essential nature as a convenient and easy-to-use liquid form of umami, without skewing flavor to a distinct Japanese taste. Particularly for individuals seeking meat-free and healthy alternatives, Japanese soy sauce is an invaluable way to provide a plant-based and fat-free savory dimension to their dishes.
Many people aren’t aware that Japan’s brewers produce a family of soy sauces that extend well beyond the widely recognized and most commonly used koikuchi variety, which is generally known as soy sauce (shoyu / 醤油). Within this diverse range, there are four other categories of soy sauce: shiro, usukuchi, saishikomi, and tamari, each offering a unique flavor profile. These varieties, reminiscent of the diverse world of fine wines, captivate with their vibrant colors, spanning from translucent pale amber to saturated purplish reds and browns, and entice with alluring aromas and complex, nuanced flavors. Similar to wines, each soy sauce category offers unique pairings that artfully harmonize with specific foods, while also allowing for creative interchangeability, resulting in an array of possible flavor outcomes for a specific dish.
The origins of Japanese soy sauce can be traced back to the late 13th century in Yuasa, a port town located on the western coast of Wakayama prefecture, where its development was inspired by the tasty liquid known as tamari that formed on top of fermenting vats of Kinzanji miso. The addition of wheat to soybeans and use of Japan’s national mold, Aspergillus oryzae, to make koji and initiate fermentation, brought about a revolutionary change in the tamari, giving Japanese soy sauce its uniquely delightful fragrance, balanced and mellow flavor, and wine-like finish. Over the centuries that followed, the recipe for Japanese soy sauce underwent further refinements, mainly at other soy sauce brewing centers within the Setouchi region, creating the family of soy sauces used today. The distinctive flavor profiles of each soy sauce category stem from different combinations of soybeans and wheat and varying durations of fermentation and aging, resulting in a range of umami savoriness, from subtle to profoundly rich, and different blends of salty, sweet, acidic, and bitter tastes.
This is just the beginning of their flavors, according to Keiko Kuroshima, one of Japan's three individuals bestowed with the title of "soy sauce sommelier" by the country's leading soy sauce brewers. Keiko explains, “Within each category, there exist endless varieties; their flavors exhibiting remarkable nuance, influenced not only by the specific ingredients and processes employed by their brewers but also by the surrounding environment.” She further emphasizes, “Japan’s soy sauce brewers are currently crafting some of the finest soy sauce ever made. They creatively combine exceptional ingredients, traditional methods, modern equipment, and a genuine passion to make innovative products that not only meet the demands of Japan’s evolving cuisine but also cater to the preferences of cooks worldwide. All of their activity is underlined by the high quality standards set for soy sauce by the Japan Agricultural Standards.”
Recently, we had the privilege of spending time with Keiko at her home on Shodoshima Island, an historical soy sauce brewing center nestled in the Seto Inland Sea. The sommelier analogy is fitting for Keiko, given her extensive knowledge of soy sauce and her vital role in the industry. In 2009, she was certified as a soy sauce sensory inspector (shoyu kan’no kensa-in / 醤油官能検査員) by the Nihon Shoyu Gijutsu Center (Japan Soy Sauce Technology Center), and diligently evaluates the color, aroma, and taste of soy sauce produced by brewers, judging their compliance with the Japan Agricultural Standards. Moreover, Keiko has devoted herself to educating consumers on how to appreciate and select soy sauce that will best pair with their dishes. In 2016, she authored the definitive guide to soy sauce, titled "Shoyu Bon," and continues to share her expertise through various writings, speaking engagements, and television appearances, and by leading tasting workshops and tours.
During our visit, we gained valuable insights into the intricacies of soy sauce, its diverse applications, and how to unlock its full flavor potential. We also had the opportunity to delve into the story behind Keiko's remarkable career, as well as discuss the latest trends within the soy sauce industry, including the exciting new products being developed today. The highlights of our conversation have been condensed and edited below.
The Family of Japanese Soy Sauces
Your profession is truly enviable, considering the irresistible deliciousness of soy sauce, which one might be inclined to savor in sips from glasses if not for its salt content. Could you share with us what inspired you to pursue this unique career path and elaborate on the preparation required to become a certified soy sauce sensory inspector and sommelier?
I was born and raised in a small town called "Hishio no Sato" (Soy Sauce Village) on Shodoshima Island, which has been a soy sauce production center since the mid-1600s and continues to be home to a large concentration of traditional brewers. However, in my younger years I didn’t have any relationship with soy sauce. My focus was solely on art, which I left Shodoshima to study at Kyoto University of the Arts. Over time, I became disheartened by the consumerism prevalent in the art world, and seeking to reconnect with the essence of creativity, I returned to my hometown after graduation.
Upon my return, I embarked on a journey to get to know my hometown better, visiting its many soy sauce brewers. The stories I heard during these visits deeply moved me and led me to ponder the meaning of artistic expression. It became clear to me that soy sauce brewers were highly expressive artists in their own right, and I felt a strong desire to support them, as many were struggling to sustain their businesses amidst intense competition and poor profitability.
I realized that a significant factor behind their struggles was the lack of awareness and understanding among consumers about the soy sauce they were using. I recognized that I could contribute to promoting the recognition and appreciation of their products by helping people select the right soy sauce to match their needs. In this way, I would also help enhance soy sauce’s integral role in Japan’s food culture and ensure that the soy sauce industry thrives and remains dynamic for generations to come.
And so, I began the rigorous program of training and examination to become a certified soy sauce sensory inspector. This has included visiting nearly 200 breweries across Japan over the past two decades to develop and refine my skills by engaging with brewers, tasting their products, and immersing myself in the atmosphere of their breweries. In terms of the number of soy sauces I’ve tasted, it’s challenging to quantify because each brewer crafts multiple varieties. Alongside physical visits, I have also explored the flavors of countless soy sauce samples.
What does a soy sauce sensory inspector do?
As a certified soy sauce sensory inspector, my role involves evaluating and rating the color, aroma, and flavor of soy sauce to ensure compliance with standards set by the Japan Agricultural Standards (JAS). This evaluation results in the assignment of a JAS quality mark, which brewers can affix to their labels.
Let me provide some quick background on the JAS standards and quality marks. They were introduced after World War II in response to the prevalence of poor quality and counterfeit soy sauce in the market due to such factors as the shortage of soybeans. For instance, some brewers were using rice instead of soybeans. The standards encompass evaluation and certification of the production methods at the brewery and for each type of soy sauce produced.
The process of evaluating a soy sauce begins by determining its appropriate category among the five recognized types. Then, a technical inspection is conducted in a laboratory to analyze its ingredients, including salt content, presence of additives, and the soy sauce's nitrogen content, which indicates its umami savoriness. Based on the results, the soy sauce receives one of three grades: Standard (Hyojun / 標準), Superior (Jokyu / 上級), or Special Grade (Tokkyu / 特級). Each higher grade represents a roughly 10% increase in umami compared to the grade below it. In addition, the Special Grade mark is exclusively awarded to soy sauce made using the traditional naturally fermented honjozo method, while the other grades allow for additives like amino acids to augment the umami content and flavor enhancers such as sweeteners. Within the Special Grade, brewers have the opportunity to achieve even higher grades called Select (Tokusen / 特選) and Special Select (Cho-Tokusen / 超特選), which also can be indicated on their labels to denote superior umami levels.
Finally, I perform the sensory inspection to ensure that the color, aroma, and flavor of the soy sauce meets the strict criteria specific to each soy sauce category and grade within each category. Such strict quality standards are unique to soy sauce and are something you don’t see for Japan’s other seasonings, proof that soy sauce is at the foundation of Japanese cuisine. The JAS standards have not only raised the overall quality of soy sauce in the market but also set competitive benchmarks that drive excellence in the industry.
Japan Agricultural Standards — Soy Sauce Quality Marks
Additionally, within the Special Grade category two higher grades are achievable: "Tokusen" (特選) and "Cho-Tokusen" (超特選), which translates to "Select” and “Special Select."
How does your role as a soy sauce sommelier differ from that of a soy sauce sensory inspector?
There are several important distinctions in the methods and purpose between a soy sauce sommelier and a soy sauce sensory inspector. In a sensory inspection, the focus is on examining the color and aroma of the soy sauce without actually tasting it, as the quality of the flavor is discernible through the aroma. The sole aim of the inspection is to identify any deficiencies against the quality standards for each grade of soy sauce, such as a burnt aroma or off-odor.
As a soy sauce sommelier, my role goes far beyond that. My interest lies in exploring and understanding the distinct flavor profile and special nuances of the soy sauce, and how it can pair with different types of food. I don't pay particular attention to deficiencies, as they can be balanced through appropriate cooking methods.
Furthermore, the personal criteria I employ as a soy sauce sommelier are much more detailed. I utilize techniques similar to those used in olive oil tasting. I’m recognized in the international olive oil world as a professional olive oil taster, which has greatly sharpened my skills in sensory evaluation. My personal criteria for tasting soy sauce involve specific conditions such as controlling room lighting and temperature, and ensuring there are no residual aromas on my hands or in my mouth. I refrain from using soap or eating beforehand to maintain the purity of the tasting experience. To fully unlock the soy sauce's flavor potential, I heat it to its optimum aromatic point of 82°F (28°C), and carefully assess its aroma and taste, utilizing expressions akin to those used in wine tasting.
This approach enables me to truly grasp the unique flavor profile of the soy sauce, with its expansive range of more than 300 possible aromatic and flavor variations, and provide well-informed recommendations on ideal food pairings.
That’s a surprising degree of nuance. To begin to better understand the flavors of Japanese soy sauces, could you guide us through the essential taste profiles of the five soy sauce categories and their general applications in cooking?
Each type of Japanese soy sauce offers complex and distinct flavor profiles. The two primary dimensions are the intensity of umami savoriness and the strength of soy sauce flavor. As you progress from shiro to tamari, the umami becomes richer and more robust, while the soy sauce flavor becomes increasingly pronounced. Furthermore, each type of soy sauce strikes a delicate balance between sweetness, saltiness, acidity, and bitterness, resulting in a unique taste experience.
Japan's three core soy sauces are koikuchi, usukuchi, and saishikomi. These variations all share a common foundation of a 50:50 ratio of soybeans to wheat, the groundbreaking development in soy sauce brewing during the Edo period (1603-1868) that distinguishes Japanese soy sauce from those produced in other Asian regions, contributing to its exceptional flavor and character.
Koikuchi, which translates to "dark-tasting," originated in the small port town of Yuasa in Wakayama prefecture and rapidly spread to Shodoshima, where large-scale production in kioke wooden barrels was underway by the mid-1600s. It’s a well-balanced, truly versatile soy sauce. Generally clearer in color and thinner in body than tamari, the original type of soy sauce, it’s also sweeter and less salty than tamari, and has a brighter taste and aroma. In fact, koikuchi’s flavor sits basically at the middle of the five soy sauce types regarding umami and soy sauce taste, as well as its salty, sweet, acidic, and bitter notes, allowing it to pair effectively with a wide range of dishes. This versatility played a pivotal role in the emergence of modern Japanese cuisine, supporting the creation of fast foods like sushi and classic dishes like teriyaki, which were developed during the Edo period. Koikuchi remains the most popular soy sauce, commanding an 80% share of the market due to its ability to create quick, tasty home-cooked meals with any kind of ingredients.
Usukuchi, meaning "light-tasting," was created in 1666 in Tatsuno, a town along the Seto Inland Sea, opposite Shodoshima in Hyogo prefecture. It undergoes fermentation and aging for at most one year, as opposed to koikuchi's two years or more, and contains 2% more salt to further suppress fermentation. It was created with the objective to produce a soy sauce with less umami and soy sauce flavor than koikuchi. Amber in color, which varies from light to darker, but always clear, it has a thinner body than koikuchi. It also exhibits beautifully light fruity aromas, reminiscent of fresh mangos, oranges, or strawberries, in contrast to the darker, richer aromas of dried persimmons, raisins, and plums found in koikuchi. Its subtler umami and soy sauce flavor better complement and enhance the natural flavors of foods, particularly fresh seasonal vegetables, the delicate flavors of the Setouchi region's seafood, and other high-quality ingredients. It also better supports delicate, light-flavored cooking preparations, like cold dishes and steaming. Usukuchi ranks as the second most popular soy sauce and is favored in the kitchens of Kyoto as well as across the Setouchi region.
At the opposite end of the spectrum from usukuchi is saishikomi, which emerged in the 1780s in Yanai City at the western end of the Setouchi region in Yamaguchi prefecture. Saishikomi is often referred to as "refermented" or "double-brewed" soy sauce, with the latter term more accurately describing the process and flavor. It’s made by mixing a fresh batch of equal amounts of steamed soybeans and toasted wheat with a finished batch of raw koikuchi soy sauce, instead of salt water as is done when making koikuchi and usukuchi. This mixture is then fermented and aged for a total of 3-4 years. In other words, it’s a soy sauce made with double the ingredients and for double the fermentation time, resulting in double the umami savoriness. Saishikomi often offers as much if not more umami than tamari, with a lower salt content than either tamari or koikuchi, and a rich, complex, luxurious flavor. During blind tastings, saishikomi typically emerges as the most popular choice due to its less salty and astringent taste profile on the palate than the other types of soy sauce. In addition, while it boasts a strong soy sauce flavor, it’s a mellow one. One of the most famous traditional brewers of saishikomi today is Yamaroku Soy Sauce on Shodoshima.
The Basic Flavor Profiles of Japan’s Core Soy Sauces
Diagram provided by Keiko Kuroshima.
What about shiro and tamari soy sauces?
Tamari and shiro are outliers. Tamari soy sauce is similar to the original liquid that pooled on top of vats of fermenting miso. It’s primarily crafted from soybeans (80-90%), with minimal or no additions of wheat, and a reduced water content compared to the other types of soy sauce. It undergoes a lengthy fermentation and aging process that can last up to 3 years or more. The result is a dark, thick, and rich soy sauce with exceptionally high levels of umami and a pronounced soy sauce flavor, with subtle notes of earthiness. Its complexity allows it to be used as a standalone dipping sauce, particularly favored with rich, fatty types of fish sashimi and grilled meats. However, its main purpose is in cooking, where it excels in deep, rich marinades, brown stocks, sauces, and gravies, and glazes. When heated, its aromatic and lustrous properties intensify, making it an excellent choice for classic Japanese dishes, like teriyaki, demi-glace, and, perhaps surprisingly, desserts. However, tamari's concentrated soybean savoriness may be an acquired taste for some individuals. On the other hand, cooks who appreciate bold flavors and create robust dishes often find tamari to be an optimal pairing. In addition, the availability of tamari sauces made without any wheat all has contributed to their increasing popularity among those following gluten-free diets.
Shiro soy sauce is the newest addition to the family of Japanese soy sauces. Believed to have originated in the early 1800s in the Nagoya area, it’s a significant departure from the other types of soy sauce by utilizing a very high proportion of wheat (80-90%) and only a small quantity of soybeans. The two ingredients then undergo a very short fermentation period, only 3 months, and no aging, resulting in the lightest tasting soy sauce in terms of both umami and soy sauce flavor. It’s also the sweetest of the five types because of the carbohydrates in the wheat, although this can be hard to detect given the salt content. Shiro’s unique combination of sweetness, saltiness, and delicate umami and soy sauce flavors make it an excellent pairing for everything. Originally, it was exclusively used by sophisticated chefs and high-end restaurants for traditional Japanese cuisine. It’s now used very broadly because of its ability to enhance the flavor of anything. I tell people to think of it as a concentrated vegetable-based consomme or bouillon.
The saltiness of soy sauce is often a focal point for cooks yet you haven’t mentioned it. Why?
Soy sauce’s salt content is an important aspect of its ability to enhance the flavor of foods. And, yes, it’s true that this is something that people often struggle with for health reasons. However, it’s more a matter of taste than actual salt content. Soy sauce’s salt content ranges from around 14% for saishikomi to approximately 18% for shiro and 19% for usukuchi. To put this into perspective, 1 tablespoon of saishikomi is slightly less than 1/2 teaspoon of salt, while 1 tablespoon of shiro or usukuchi is about 2/3 teaspoon of salt. Keep in mind that 1 tablespoon of any type of soy sauce in a dish is already a substantial amount.
As you can see, the salt content of soy sauce varies among the different types, but the differences are not remarkably significant, despite what people often think. Shiro and usukuchi do tend to taste much saltier than the other soy sauces because their saltiness is not masked by high levels of umami as it is for the other types of soy sauces. The actual saltiness of shiro and usukuchi is consistent with their ability to delicately enhance the taste of the foods they accompany. Their higher salt content means less soy sauce is required to properly season dishes with salt, thus further lowering the amount of umami and soy sauce flavor they add to a dish
Still, low-sodium and less-sodium types of soy sauce salt are growing in popularity. I don’t recommend them. They’re made with the standard required amount of salt for each type of soy sauce but become less salty through a mechanical process of desalination once fermentation is completed. This can affect their flavor. Instead, I tell people to focus on their cooking methods. Use soy sauce in moderation. Add acids like lemon, other fruit juices, or vinegar, herbs, and spices to make their dishes taste better. Or use saishikomi because of its low salt content.
Salt & Umami Content of Japanese Soy Sauce
What about the significance of soy sauce's color? You mentioned that color plays a key role in evaluating the different types of soy sauce against JAS standards. Additionally, some people refer to usukuchi as "light-colored" soy sauce and koikuchi as "dark-colored" soy sauce and believe it's important when choosing which soy sauce to use. How important is color?
Usukuchi is typically lighter in color compared to koikuchi, and shiro is even lighter. Both usukuchi and shiro won't impart the same level of color to dishes as koikuchi and the other soy sauces do. This aligns with usukuchi and shiro's primary purpose of allowing the natural qualities of ingredients to shine through. The deeper color imparted by the other soy sauces is consistent with their role in creating visually hearty and flavor-rich dishes. While color can be a consideration, it shouldn't be the primary one. It best serves as an indicator of the level of umami and soy sauce flavor a soy sauce contributes to a dish. Therefore, it's more appropriate to translate usukuchi as "light-tasting" and koikuchi as "dark-tasting."
Thank you for sharing those insightful details. They truly highlight the unique qualities and versatility of each soy sauce type, which is inspiring. In order to enhance our understanding of selecting the appropriate soy sauce for different cooking purposes, are there any general guidelines and principles to consider when choosing among the various types, especially for non-Japanese cuisines?
To help foreign cooks understand and use Japan's soy sauces, I often draw a parallel between the different types of soy sauce and wines. Just like white wines, shiro and usukuchi are ideal for dishes featuring white fish, chicken, eggs, vegetables, cream-based sauces, and delicate flavors. They provide a subtle boost of umami savoriness and don’t overpower the other ingredients with a strong soy sauce taste. A cook should also consider using shiro and usukuchi when working with light-tasting stocks, oils like canola and olive oil, and delicate seasonings such as honey, lemon juice, white wine and apple cider vinegars, and herbs like shiso, parsley, chives, basil, dill, and tarragon. Shiro and usukuchi work wonderfully in carpaccio, salad dressings, and noodle, pasta, and rice dishes, including risotto.
On the other hand, koikuchi, saishikomi, and tamari soy sauces can be likened to red wines. They excel in marinating, grilling, and braising red meats, including red-fleshed fish like tuna, adding depth to hearty soups and stews, crafting robust sauces, and creating glazes. These soy sauces also best complement recipes that incorporate fats, stronger-tasting oils like sesame oil, richer seasonings like brown sugar, red wine and balsamic vinegars, and bold herbs and spices such as wasabi, ginger, oregano, rosemary, paprika, and black pepper. They work particularly well when making BBQ, stir-fries, classical Japanese dishes like teriyaki and sukiyaki, and as toppings for desserts, which brings out their caramel and chocolate-like flavors.
Still, it's important to note that each type of soy sauce is highly versatile. Each can be used in any dish, and can lead to unexpected flavors that complement the dish perfectly or pleasantly surprise you with an unexpected new flavor. For example, while darker, richer soy sauces like saishikomi and tamari tend to work best when making Chicken Teriyaki, using shiro instead brings out the sweetness of the other ingredients and results in a harmoniously elegant rather than hearty tasting dish.
The different types of soy sauce can also be combined to build and layer umami and flavor in a dish. When making Kake Udon Noodle Soup, each type of soy sauce results in a uniquely tasty broth. To get the exact flavor you like, try combining soy sauces.
I always encourage people to experiment with the different types of soy sauce. The beauty of soy sauce is that regardless of the type you choose, you are unlikely to encounter major disappointments.
I'd love to hear your insights on enhancing a simple marinara sauce for pasta using soy sauce. Despite the fact that tomatoes are an umami-rich vegetable, the sauce can often taste insipid. Or, it can taste too acidic even though tomatoes are a very sweet vegetable. Which type of soy sauce would you recommend for this recipe?
When making marinara sauce using fresh tomatoes, I use shiro or usukuchi soy sauces. They enhance the tomatoes delicate flavors, while underpinning the inherent umami in tomatoes, creating a light and refreshing sauce I serve over cappellini. When using canned tomatoes, which I often do, I use saishikomi or tamari soy sauces as the secret ingredient. They best underpin the extra richness and deeper flavor of the canned tomatoes. Let me note that adding herbs like basil, some vegetables, and seafoods or meats to the sauce doesn’t change my recommendations.
Now, let’s turn to the soy sauce brewers and tap your extensive knowledge about what’s available in the market. It’s a pretty well known fact that there has been a dramatic decline in the number of brewers, primarily due to increased competition and the concentration of market share among major commercial brands. Despite this, there are still over a thousand soy sauce brewers in Japan, each with its unique offerings and styles. Could you provide some guidance on how consumers can choose the right soy sauce brand for their culinary needs and preferences?
That’s correct. There has been a significant decline in the number of soy sauce brewers since the mid-20th century, with only 1,066 breweries remaining in 2021 compared to 6,000 in 1955, according to the Japan Soy Sauce Association. The market is now dominated by the top 6 major brand commercial breweries, accounting for approximately 60% of the soy sauce produced in Japan. Additionally, the top 15 companies, which includes another 9 semi-major commercial breweries, produce about 75%. It’s important to understand that it wasn’t only price competition that forced both large and small breweries out of the market. It was also the inability of many breweries to meet the quality expectations of consumers that followed implementation of the JAS standards.
But, with some 1,051 other soy sauce brewers active across Japan beyond the major and semi-major brands, there’s still a lot to choose from. The market remains very diverse, and the quality of soy sauce being produced is high across the board because the JAS standards have been in place for over 60 years.
What’s more, it’s a dynamic industry. Among the 1,051 other brewers, you can find large and medium-scale companies specializing in certain types of soy sauce like shiro, uskukuchi, and saishikomi or who are household names in their regions for their style of koikuchi. Because koikuchi is so widely consumed, its flavor varies considerably, with some, for example, having more salt than usukuchi and others being as strong and rich as saishikomi.
Then there are the many smaller artisanal brewers that prioritize meticulous craftsmanship and offer unique styles. Family-owned breweries that focus on traditional recipes, and farm breweries that cultivate their own beans and wheat, often employing organic methods. There are also boutique breweries that produce limited quantities of innovative and high-quality soy sauces, employing unconventional brewing techniques, utilizing different grains, and exploring experimental flavors to create distinctive products.
What can you tell us about the difference in quality and flavor between soy sauce produced by major brands versus those crafted by specialized and artisanal brewers?
With the major brand brewers, you know you are getting a quality product as they all use the traditional honjozo brewing method. The honjozo brewing method is a legally regulated process that involves fermenting the four basic ingredients, soybeans and wheat, along with salt and water, and allowing the mixture to undergo a natural fermentation and aging process, which is a minimum of six months for koikuchi. This method ensures the development of deep flavors, complex aromas, and a well-balanced umami profile.
However, the major brands tend to offer a middle-of-the-road, standardized flavor that is always constant as they strive for efficiency of production. Additionally, there is little difference in flavor among the major brands, but you can find some. For example, Yamasa, which traces its roots back to Yuasa and is the second largest brewer after Kikkoman, has surprisingly strong flavor characteristics, including herbal notes. The primary advantages of major brands are their reliability and convenience, as they are typically readily available in all five types across the nation and are increasingly accessible abroad.
It’s with the other brewers that you can often get better quality products and, more importantly, an incredible range of unique and nuanced flavors. These flavors are a testament to their craftsmanship, ingredient choices, and the myriad process variables influencing soy sauce's taste, including the unique bacteria and yeasts thriving in their breweries.
A very important development in recent years has been the revival of the use of large kioke wooden barrels in which to brew soy sauce. These barrels are ecosystems harboring beneficial and flavorful microbes in their wood that add unique, nuanced tastes to the soy sauce in addition to aiding its fermentation. While only 1% of the soy sauce produced today is made in kioke barrels, 281 companies—both large and small—are embracing this traditional method once again, recognizing its ability to enhance the flavor profiles of their soy sauces.
However, I’d like to point out that adhering to completely traditional equipment and processes doesn't always yield the best or most distinctive soy sauce. Contemporary steamers have proven to be exceptionally efficient in extracting the umami essence from soybeans. Modern cooling equipment is instrumental in assisting brewers in crafting purer soy sauces, including unpasteurized versions. For instance, shiro is often deliberately left unpasteurized to preserve its delicate flavor.
The result of these myriad choices is an astonishing spectrum of unique and often intriguing aromatic profiles. Within this diverse realm, you'll encounter soy sauces with enchanting floral bouquets, delicate fruity notes imbued with the essence of fresh fruits, and those boasting toasty and smoky undertones. Some varieties may evoke the warmth of caramel, chocolate, or coffee. Others transport you to the realm of incense-laden temples, lush forests, or the briny shores of the sea. Certain soy sauces may evoke cherished memories of grandmother's kitchen or stir feelings of nostalgia, as if you're strolling down a bustling arcade of yatai (food stalls) during a vibrant matsuri festival.
Is there a role in one’s pantry for both the major brands and artisanal soy sauce?
From my experience, it’s rare for people to have both major brand and artisanal soy sauces in their pantry. Most people don’t choose soy sauce by its taste. Their use of soy sauce is more a difference in mindset, such as price and convenience, than taste. But there are some people who use a major brand for cooking, then bring out an artisanal soy sauce as a condiment for special uses like sashimi and sushi or for special occasions. I don’t recommend this approach because soy sauce’s flavor deteriorates over time once opened. It loses its nuances and oxidizes past 6 months. However, if someone still wishes to use both, I suggest reserving the artisanal soy sauce for finishing touches on such dishes as cold tofu and other cold preparations. Or, similarly, use it as an ingredient in salad dressings, dipping sauces, and lightly-cooked dishes.
It's worth mentioning that artisanal soy sauce isn't an expensive product. If you find one you enjoy and it makes you happy, use it for all your cooking needs.
With the overwhelming selection of soy sauces available, what guidance can you offer for effectively navigating this extensive variety? How valuable are the JAS marks as reference points for consumers seeking soy sauce?
The JAS mark affixed to labels of soy sauce is a valuable tool for consumers when purchasing soy sauce. The JAS logo provides assurance that the soy sauce is authentic and produced under strict supervision at a trustworthy brewery. In addition, the quality grades provide information not only about the flavor but also the production method. For example, if you’re looking for an all-natural soy sauce, seek out those carrying a “Special Grade” (Tokkyu / 特級) JAS mark, as it is reserved for soy sauce made using the traditional naturally fermented honjozo brewing method. The other grades allow for soy sauce that incorporates additives like amino acids to heighten umami and flavor enhancers like sweeteners. One example is amakuchi, or "sweet soy sauce," which is popular in western Japan and Kyushu Island and typically contains both amino acids and sweeteners.
Having said this, there is a growing trend in the industry not to use JAS marks. JAS certification is voluntary, and the number of soy sauces being tested has declined to 52.8% in 2020 from 91.6% in 1980. The reason is many small artisanal brewers don’t want to take the time and spend the money on the certification process, especially if they know they are making quality soy sauce and have an established reputation among their customers. In addition, their unique soy sauces may have characteristics that fall outside industry standards. For example, a brewer may make a very high quality usukuchi whose color deviates from the strict JAS standard by being a bit too dark.
One way around this is to check for a JAS mark on their other types of soy sauce. The baseline JAS testing is certification of the brewery. If one type of soy sauce carries a JAS mark, it means that the brewery is making their soy sauces according to quality production methods. And, if you’re particularly concerned about whether a soy sauce is naturally-brewed or contains amino acids, look at the ingredients on the label. “アミノさん” (aminosan) indicates the soy sauce contains amino acids.
JAS Organic Mark
JAS is presently exploring the introduction of new quality marks aimed at upholding the industry's rigorous standards for emerging soy sauce products. Alongside the existing JAS marks, a logo is already in place to signify whether a soy sauce is organic. An important addition being considered is a mark denoting soy sauce that has been brewed in kioke barrels.
But let me repeat, soy sauce produced today in Japan is generally high quality. It’s not necessarily true that soy sauce without the JAS mark is not good enough. Ultimately, the choice should be a matter of personal taste and preference. If you like a particular soy sauce, trust your own judgement, buy it, and use it.
What particular recommendations or tips can you provide for those seeking to explore the world of artisanal soy sauces?
Part of the appeal of artisanal soy sauce is the hunt for the one you love. Artisanal soy sauce is a reflection of the brewer's taste and their unique vision for their product. Therefore, it's essential to seek out the soy sauce that resonates with your preferences or whose story you’d like to support.
The good news is that there's an increasing wealth of information available about Japanese artisanal soy sauces. Even better, most artisanal breweries welcome visitors. Brewers are generally eager to share their knowledge, provide tours of their facilities, and explain their production processes and offerings. Almost all of these breweries have shops and tasting rooms.
Visiting these breweries is not only enjoyable but also enlightening, as you can often discern the brewer's personality in their soy sauce. For instance, someone like Yasuo Yamamoto, the creator of Yamaroku Soy Sauce, exudes boundless energy and boldness, which is reflected in his bold-flavored soy sauce. On the other hand, the Okamoto brothers, who make Okamoto Soy Sauce on Osaki Kamijima Island, have a more reserved demeanor, preferring to shine a spotlight on fellow artisanal brewers. This subtlety and humility is mirrored in their refined soy sauce, which showcases the natural flavors of the ingredients.
Can you tell us about your most recent exploration in the world of soy sauce? What aspect or particular sauce have you been delving into lately?
At the moment, I’m very interested in shiro and exploring its culinary applications. One shiro I’m focused on is that made by the Morita brewery in Nagoya, shiro’s birthplace. It’s a Special Select (Cho-Tokusen / 超特選) grade of shiro with an unusually elegant sweet taste and aroma. The Morita brewery is one of the oldest in Japan and was established in 1664 by the family of Akio Morita, the founder of Sony Corp. Today, the brewery is highly regarded for its production of soy sauce, miso, and other seasonings.
As we conclude, let's discuss the future of Japanese soy sauce. As you’ve outlined, Japanese soy sauce has continually evolved throughout its history to meet diverse culinary preferences and cooking styles. Looking ahead, what do you foresee as the next developments for Japanese soy sauce?
The most significant trend I’m seeing in the soy sauce industry is Japanese soy sauce’s adaptation and refinement to cater to foreign tastes and preferences. In recent years, Japanese soy sauce has gained global popularity, and is currently experiencing its fastest growth abroad. The demand for organic soy sauce abroad, in particular, is growing faster than Japan’s brewers can keep up with. In addition, brewers in Japan have developed halal versions of soy sauce to meet the dietary requirements of Muslim consumers. In the United States, Kikkoman has introduced a gluten-free version by brewing soy sauce with umami-rich tomato as a base.
The localization of soy sauce is going much deeper than that. An influential factor has been the chefs at Noma, the renowned restaurant in Copenhagen, who have embraced a culture of fermented foods, advocating an exploration of locally-derived fermented seasonings that incorporate Japanese fermentation methods. Aligned with this, many international restaurants are seeking assistance from Japan’s soy sauce brewers to develop their own unique house soy sauce. The Japanese brewers are either producing the soy sauce on their customers behalf or acting as consultants, with the soy sauce being made locally.
This kind of production will lead to an even greater diversity of Japanese types of soy sauce. While Japan maintains strict control and standards over soy sauce sold in Japan, that distributed or produced abroad is not subject to the same regulations. I expect this trend to result in country-specific variations that offer unique and distinct flavors from Japan. This will provide consumers with a rich tapestry of soy sauces from around the world to explore and enjoy.
In addition to being a major center of soy sauce brewing, Shodoshima Island is Japan’s leading producer of olive oil, and Keiko has also become an olive oil sommelier, which she says has a remarkable affinity with soy sauce.