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A Celebration of Soy Sauce

Soy sauce is essential in many culinary traditions—and no two styles are the same.


Published Jan. 26, 2023.

What You Need To Know

Soy sauce originated 2,000 years ago in ancient China, where it was created to stretch salt, an expensive commodity at the time. After making its way to Japan in the seventh century, it eventually spread throughout East and Southeast Asia and across the globe. 

From the funky and papaya-like flavors of see ew khao in Thai cuisine to the earthy and sharp toyo common in Filipino food, flavors and aroma vary greatly from one style of soy sauce to another and go far beyond Kikkoman, the top-selling brand in the United States. No matter how much you know about soy sauce, there is always more to learn. Come along with us as we celebrate this incredible ingredient and find new styles to expand your cooking repertoire. 

How Soy Sauce Is Made: Artisanal versus Commodity 

Chinese soy sauce was originally made with soybeans only. The Japanese method added wheat, which speeds up the fermentation process and lends a touch of sweetness from starch. That subtle sweetness has become part of the characteristic flavor profile of soy sauce, and these days most contain wheat.

Small-batch artisanal soy sauce typically begins by mixing soybeans, wheat, salt, water, and a mold called Aspergillus oryzae (referred to as qu in Chinese and koji in Japanese). The mixing process creates a mash, which is regularly churned by hand during a fermentation stage that can last from six months up to several years. In some places, fermentation takes place inside locally made clay barrels or wooden barrels, which impart aromas and flavors unique to the locale because of the presence of particular microbes, according to Christopher St. Cavish, a culinary consultant based in Shanghai. 

The production of commodity soy sauce looks a little different. Large quantities of soybeans, wheat, salt, water, and enzymes ferment in steel containers. The process is considerably faster, usually lasting several weeks to a year. Soy sauce made this way is sometimes labeled “naturally brewed.” 

The fastest method of all results in something called “hydrolyzed” or “chemically produced” soy sauce. Soy and wheat protein are heated with concentrated acid, a process that takes no more than a few days.

Fermentation Equals Flavor 

During the fermentation process of all soy sauces, the soy and grain proteins are split into their component amino acids. These flavorful compounds—primarily one called glutamic acid—create the umami-rich taste. As time passes, the flavor intensifies as the continued fermentation generates new flavor compounds. The longer a soy sauce is fermented, the more complex it becomes. We noticed this while tasting, preferring more multidimension...

Everything We Tested

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The mission of America’s Test Kitchen Reviews is to find the best equipment and ingredients for the home cook through rigorous, hands-on testing.

Valerie Sizhe Li

Valerie is an assistant editor for ATK Reviews. In addition to cooking, she loves skiing, traveling, and spending time outdoors.