Soy sauce. 

You see the bottles on the shelf of any grocery store you enter. Chances are you probably have some in your fridge right now. In fact, soy sauce may be such a familiar thing to you that you might be wondering why you’re even reading about it. 

But if you stop to think about it for just a moment, do you actually know what’s in this well-known umami-packed sauce? Where did it originate? How is it made? And how can you use it in the kitchen to deepen flavors and create delicious, savory food? 

We’ve got all the answers you’re looking for, plus a few more interesting tidbits that any good cook (and yes, that’s you!) should know about. 

What is Soy Sauce?

During the Zhou dynasty of China, over 2,500 years ago, salt was a scarce and expensive commodity, even for imperialistic dynasties. A method was created to extend salt by fermenting it with soybeans and fish, and sometimes grains. When Buddhism, and with it vegetarianism, spread from India to China around 220 BC, the fermentation process became split into two different methods; one which used animal products and the other which used soybeans. Thus, soy sauce was created. 

At that time, Chinese Buddhist cuisine was relatively bland. Pungent vegetables typically used to spice up Chinese cuisine, such as onions, leeks and garlic, were not used by Buddhists as they were believed to overexcite the senses. Soy sauce, with its salty, umami taste, quickly became popular. As Buddhism spread to Japan and other parts of Asia, soy sauce travelled along with it, taking on various forms unique to each country where it was used. 

What is Soy Sauce Made From?

Soy sauce is traditionally made from five ingredients; soybeans, wheat, salt, water, and fermenting agents. The soybeans are soaked in water, the wheat is roasted and crushed, and then the two are mixed together with a culturing mold, usually Aspergillus. After being left for 2 to 3 days to develop, water and salt are added, and the entire mixture then ferments in a tank for 5 to 8 months, sometimes even longer. 

During this fermentation period, enzymes in the culturing mold turn the wheat, soy, and salt proteins into amino acids. These amino acids react with sugar in the soybeans and create a chemical reaction called Maillard browning, which is how soy sauce gets its color, flavor, and smell. Maillard browning occurs all the time in your kitchen; it’s responsible for the beautiful golden color of fried dumplings, cookies, and crispy tofu. Though with the absence of heat in the fermentation process of soy sauce, Maillard browning takes a bit longer to happen than, say, with a browned bit of toast. 

When the fermentation process is complete, the thick soy paste is spread out onto cloth and pressed to release the liquid which is then pasteurized and bottled. 

The traditional method of brewing soy sauce is a lengthy and complicated process. As we’re known to do, people found a faster and less expensive way to make the popular condiment using hydrolyzation, a chemical reaction where water molecules break down chemical bonds. The production of soy sauce through hydrolysis takes only a few days, but the end product lacks the depth of flavor found in traditionally brewed soy sauces. Hydrolyzed soy sauce also contains preserving chemicals to extend shelf life. 

What Does Soy Sauce Taste Like?

Soy sauce is salty with a strong umami (savory) flavor, a little sweetness, and a slight hint of bitterness. The salt comes from the brining liquid, while the starch in the soybeans adds sweetness. The characteristic umami (meaning “tasty” in Japanese) flavor comes from the amino acids which are produced during fermentation to form monosodium glutamate (MSG). 

There are hundreds of varieties of soy sauce available today. The flavor profile of each is different depending on the ingredients, creation process, and the country or region of production. 

Light Soy Sauce

This is the most commonly used soy sauce in Western culture. If you have a bottle of soy sauce in your fridge right now, it’s most likely light soy sauce. It’s thin, dark brown and very salty. 

Dark Soy Sauce

After the brewing process, this soy sauce is aged for a longer period and has either molasses or caramel added to it. This creates a thicker and sweeter sauce with a blacker color. It typically is not as salty as the light variety because the soy flavor of the beans takes center stage. 

Thick Soy Sauce

Sometimes known as soy paste. Thick soy sauce is sweeter and thicker (of course) than other types of soy sauce due to the added amounts of sugar and wheat used during the fermentation process. 

Where and How is Soy Sauce Used?

Soy sauce is commonly used in Asian cuisine as an ingredient for sauces and marinades. The two most frequently used varieties of soy sauce are light and dark. Light soy sauce is usually used in everyday cooking for dishes like fried rice and stir-fries. If a recipe calls for soy sauce to be used, it almost always refers to light soy sauce. 

Dark soy sauce has a much stronger soy flavor which pushes the salty flavors back a bit. Because it can be overpowering, dark soy sauce should be used only if a recipe specifically calls for it and not as a substitute for light soy sauce. 

Though most often used in Asian dishes, the versatility of soy sauce means it can add great flavor to a wide variety of cuisines. Mixing soy sauce with sesame oil, vinegar, and fresh herbs and spices makes for a simple and healthy salad dressing. When sauteing, you can replace oil with a mix of soy sauce and water to cut down on the fat content. The water-soy sauce mixture can also be used to coat vegetables before roasting. 

Soy sauce can be an ingredient in BBQ sauce like the one used for these mouth-watering tempeh ribs from Shane over at Shaneandsimple.com. The popular vegan food blogger, ElaVegan, uses soy sauce to create a rich umami flavor in her vegan mushroom risotto with chickpeas. Bianca Zapatka’s vegan stroganoff calls for several tablespoons of soy sauce to be used alongside mustard and white wine to create a cozy and creamy sauce that’ll make you want to lick the plate when you’ve finished eating. 

What is the Difference Between Tamari and Soy Sauce?

Often times in recipes you might see tamari listed as an alternative to soy sauce. This is because tamari is also made from fermented soybeans and is similar in flavor and color. The major difference is tamari, a Japanese form of soy sauce, does not use wheat in the fermenting process, making it a popular choice for those with gluten intolerance. 

To make up for the lack of wheat in the fermentation process, tamari is made with twice the amount of soybeans. This gives it a darker color and richer flavor than light soy sauce. Tamari can be used in any dish that calls for soy sauce, but you may want to decrease the amount used because of its more robust flavor. 

Is Soy Sauce Healthy?

Many people have health concerns about soy sauce; usually regarding the salt content and presence of MSG. 

One tablespoon of soy sauce contains about 38% of the current RDI (recommended daily intake) of sodium. But the same amount of table salt contains 291% of the RDI for sodium, so it’s actually healthier to reach for the bottle of soy sauce over the container of salt. 

If you really want to cut down on sodium in your diet you can buy low-sodium soy sauce, or opt for using tamari which has a lower salt content. 

For a long time, it was thought that MSG often found in Chinese food was the cause of MSG symptom complex which included headaches, weakness and heart palpitations. However, a 2015 study on MSG did not find significant evidence to show that it was responsible for these symptoms. 

The presence of MSG itself in soy sauce is not a cause for concern. However, most soy sauces which have added MSG are chemically produced. It may cost a little bit more, but opting for a naturally fermented soy sauce is the healthier choice. And you’ll definitely notice the difference in flavor.