Soybeans –The Cornerstone of Japanese cooking
Japanese cuisine is rich in the fruits of the land and the sea. From rice to fish, many healthful ingredients find their way to the Japanese dinner table. But one plant stands out from the rest.
The soybean comes in many consistencies, colors, smells, and textures. In one form or another, soy is nearly always present in Japanese food.
The plant is so well integrated into the culture and deeply intertwined with the spiritual history of the island that soy products became an unavoidable ingredient in many traditional meals. In fact, the English word for soy even originates from “shoyu”, the Japanese name for soy sauce.
However, in Japan, there are many more ways to consume soy than just soy sauce. From vegetable oil, over fermented beans, to soy-based cheese, soy is definitely an impressively versatile part of Japanese cuisine.
Soybeans as a Protein Source
Unlike the western world, the Japanese never relied on meat and dairy products as a source of protein. For some 1200 years, eating animal meat was frowned upon and even banned by law. At first, only Buddhist monks ate strictly vegetarian. Though the native Shinto religion dominated the islands, Buddhist philosophies of respect for life became an integral part of the culture. Besides, it wasn’t easy or profitable to invest in livestock on the mountainous land anyway.
It’s said that proteins act as our body’s building blocks. The nutrient is pretty much necessary in the human diet.Instead of meat, fish became a major source of protein. The second place, right after fish, belongs to beans. Specifically, the soybean.
Soy is an excellent protein source – protein constitutes up to 33% of soy’s nutritional makeup. And since it’s such a versatile plant, it became integrated into the Japanese diet in various shapes and forms.
The Most Popular Soy-Based Foods in Japan
The soybean can be processed in many ways. The beans may be cooked, fermented, processed into milk and cheese, pressed into oil, or ground into a paste. All of these ways of processing give us well-known soy-based staples found in Japanese pantries.

Soy Sauce (醤油)
“Shoyu”, the Japanese word for soy sauce became the very origin of the word we use for the plant in the west – soy.
This world-famous dark brown sauce hardly needs an introduction. It’s used as a dip in many Asian recipes, and its savory, umami flavor is steadily getting integrated into international cuisines as well.
In Japan, soy sauce is used as a base for soups like shoyu ramen and udon, as a dip with many snack foods, sushi, yakitori, and sashimi platters, as a salad dressing, and as a flavor enhancer for almost anything that might be cooking.
Soy Sauce Varieties
Soy sauce comes in more than one variety, and it universally goes through a long fermentation period. Produced in different regions in Japan or using different production methods, the five basic kinds of shoyu have fermented soy and wheat as their base.
- The koikuchi (濃口) sauce makes up to 80% of soy sauce produced domestically. It’s thick and dark, with a rich umami flavor and a hint of sweetness. That universal taste makes it the preferred condiment for most Japanese dishes.
- Usukuchi (薄口), or thin soy sauce makes up for another 14% of domestic production. With a shorter fermentation period, usukuchi is lighter-colored, less fragrant, and saltier than common soy sauce. It doesn’t alter the color and helps bring out the natural flavors of other food.
- Tamari (たまり) sauce is even darker, thicker, and more fragrant than the common koikuchi soy sauce. It’s made with little or no wheat, which makes it the right pick for gluten intolerant people. Traditionally, tamari sauce was the byproduct of miso production. Out of all soy sauce kinds produced in Japan, Tamari is the closest to the original recipe that takes roots in China. This thick, reddish sauce is the preferred sashimi dip, and it’s also the preferred sauce for grilling.
- Sashikomi (再仕込) or refermented soy sauce is a dipping sauce that brings the most powerful punch of flavor. Instead of starting the process in brine, regular soy sauce is used to create this double-brewed soy sauce. It’s not used for cooking. Instead, it’s one of the favorite condiments used to enrich tofu, sushi, and sashimi.
- Shiro (白) means “white” in Japanese, and it’s the perfect name for the extra-light shiro shoyu. The pale sauce is made of wheat with very little soybean, giving it a different color and a unique taste among soy sauces. It’s sweet and has a somewhat bland flavor. It’s a favorite pick for pickles and rice crackers, and it’s also frequently used in soups.
Along with these basic varieties, soy sauce is often mixed with other ingredients to create unique condiments. For example, Ponzu sauce, a common meat and dumpling dip, is basically shoyu with added vinegar and citrus fruit juice. Tsuyu, a range of dipping sauces used for stews, tempura, and noodles are another example. They’re made of soy sauce combined with mirin, sugar, dashi stock, or other ingredients that bring out the umami flavor.
Miso (味噌)
Though you may instantly think of the soup, miso soup is only one of the dishes you can make with miso paste. This traditional seasoning is made of fermented soybeans, a bit of salt, and the fungus Aspergillus oryzae. Barley, seaweed, or rice are sometimes added to produce specific types of miso.
Miso is a thick paste, often used as a spread or a sauce, but most commonly as a base for soups and marinades. Its taste is salty and rich with umami, so miso gets added to many meals as a flavor enhancer.
Mixed with dashi soup stock, it makes miso soup, a world-famous Japanese dish. It’s often added to deep-fried meat cutlets to make a dish called miso katsu.
Miso comes in three varieties:
- Mild-tasting white miso, made with a large amount of rice. It’s very light and sweet, often used in condiments. This type of miso is a favorite in the Kansai region, which is home to large cities like Osaka and Kyoto.
- Red miso undergoes a longer fermentation period, so it also comes with a very strong umami flavor. It’s ideal for soups and braises, but the taste can be too overpowering for a condiment. This type of miso is very popular in Nagoya.
- Yellow miso is exactly in between – made with barley, this type has a strong but not overpowering flavor. It’s the most versatile choice of miso paste that can be used both as a condiment and in soups and marinades. This is the preferred type of miso in the Kanto region (Tokyo and the surrounding cities).

Tofu (豆腐)
People from Asian countries didn’t really consume dairy products as part of their regular diets in the past. Even today, when many western recipes are integrated into the Japanese lifestyle, animal milk and cheese aren’t very widely consumed.
But that doesn’t mean the Japanese don’t eat curd. Tofu is quite similar to bland, odorless cheese in texture – but it contains no animal products at all. Made of pressed soy milk, tofu is the vegetarian filler food widely used in Japanese cooking.
The magic happens when you mix it with other ingredients – it soaks up the flavor and enhances it. It’s frequently added to various soups, stews, and meal platters. In Japan, you can even find tofu served on its own (served with sweet or savory toppings) since it has a rich taste and an enjoyable texture.

Edamame (枝豆)
All the other foods on the list are soy products – since there’s only one way the Japanese eat the soybean as-is: in the form of edamame. Cooked, immature soybeans, eaten straight from the pod.
It only takes a short preparation by boiling or steaming. In other East Asian countries, edamame is typically salted, but instead of shaking the salt on top of the pod afterward, the Japanese blanch the pods in salty water.
Edamame is an interactive snack where you need to take the beans out of the pod. You may also find mukimame, shelled soybeans that are easier to consume (but arguably way less fun).

Natto (納豆)
Natto is the kind of food that people either absolutely love or passionately hate. You’ll know which group you belong in the moment you first feel its pungent odor. Some people compare the smell to aged cheese, but the sticky natto slime is an experience unlike any other.
This sticky soy dish is simply served with a bowl of rice, often mixed with soy sauce or karashi mustard. That makes it a simple, quick breakfast, especially since most Japanese buy natto mass-produced. Packaged in small 50-gram servings, mass-produced natto is popular because the dish requires a complex fermentation process. Soybean fermentation is helped by a specific bacteria named natto-kin, and any other contaminant could completely alter the process.
In Japan, even the people who dislike natto try to eat it once in a while due to its many health benefits. Compared to raw soybeans, natto comes with a lower calorie count and is augmented by branched-chain fatty acids (BCFA) that form during the fermentation process.

Kinako (黄粉)
Soy can add a delicious, nutty flavor to your desserts as well.
The Japanese call it kinako – the soybean flour. The production process is simple – roasted soybeans are ground to a powdery texture.
On its own, kinako isn’t sweet, but it’s a tasty addition to many desserts. Warabi mochi, for example, is a jelly-like cake covered with kinako. The popular dango, sweet skewered dumplings, are sometimes topped with kinako too.

That’s Soy Good
Along with rice, fish, and tea, soy products are a must-have staple in most East Asian pantries.
The soybean is, in a way, the magic ingredient found in almost every Japanese recipe. In one form or another, soy is always there to enhance flavor and bring plenty of nutritional value to your meals. It’s a tasty, healthful, versatile bean – what’s not to love!
Feel free to leave a comment below if you have any questions or want to share your experience with soy!