Soy Sauce

A dark, salty, deeply savory liquid brewed by fermenting soybeans and wheat with salt and mold — the foundational seasoning of East Asian cooking. Rich in umami, it seasons, colors, and rounds out everything from a bowl of rice to a slow-braised roast.

What it is

Soy sauce is a fermented seasoning traditionally made from soybeans, wheat, salt, water, and a cultured mold called koji (Aspergillus oryzae). The koji is grown on cooked soybeans and roasted wheat, then combined with brine to make a mash called moromi, which ferments and ages for months as enzymes and microbes break the proteins and starches into glutamates, amino acids, and aromatic compounds. The result is pressed and pasteurized into the familiar salty, umami-rich brown liquid. Naturally brewed soy sauce is complex and layered; cheaper chemically hydrolyzed versions skip the long ferment and taste flatter and harsher. Color, saltiness, and body vary widely by style and region.

History & origin

Soy sauce traces back over two thousand years to China, evolving from earlier fermented soybean and fish pastes (jiang) used to preserve and season food. It spread through East and Southeast Asia, reaching Japan by around the 7th century, where Buddhist influence and local brewing refined it into shoyu. Dutch traders carried it to Europe as early as the 17th century, where it became a prized seasoning and, some say, an ancestor of Western bottled sauces. In 1917 the Mogi and Takanashi families’ brewing traditions consolidated into what became Kikkoman, now the world’s best-known soy sauce brand.

Where it comes from today

Soy sauce is brewed across East and Southeast Asia and, increasingly, worldwide. Chinese styles split into light (sheng chou), thinner and saltier for general seasoning, and dark (lao chou), aged longer and often sweetened with molasses for color and body in braises. Japanese shoyu comes in styles from the standard koikuchi to lighter usukuchi and the wheat-free tamari, a byproduct of miso-making that is richer and often gluten-free. Major brands include Kikkoman (Japan), Lee Kum Kee and Pearl River Bridge (China), and premium naturally aged makers throughout the region.

How it’s used today

Soy sauce is everywhere in East Asian kitchens: it’s the dip for sushi and dumplings, the seasoning in stir-fries and fried rice, and the base of marinades, glazes, and braises like Chinese red-cooked pork. Light soy seasons without darkening; dark soy adds deep color and a hint of sweetness to lo mein and braised dishes. Beyond Asian cooking, a splash deepens gravies, soups, marinades, and even burgers with a hit of umami. Tamari is the go-to for gluten-free cooking and gives a rounder, less sharp flavor.

Make your own

Soy sauce can be brewed at home, but it’s a serious months-long project: you culture koji mold on soybeans and wheat, combine it with brine, and let the moromi mash ferment and age for six months to a year or more, stirring and tending it throughout. The koji cultivation and long aging put it well beyond a weeknight effort. A from-scratch recipe is on the way for the patient.

Substitutes (if absolutely necessary)

• Tamari — a wheat-free soy sauce; nearly identical use, richer and less sharp, and the standard swap for gluten-free cooking.
• Coconut aminos — soy- and gluten-free, milder and a touch sweeter with less salt; good for those avoiding soy, though thinner in umami.
• Worcestershire sauce — in a pinch for savory braises and marinades it lends salt and umami, with more tang; see Worcestershire Sauce.
• Liquid aminos or a pinch of miso thinned with water — both supply the salty-savory backbone when no soy sauce is on hand.

Where to find it

• Local store: international/Asian aisle and often the general condiment shelf; Kikkoman is nearly universal, with light, dark, and tamari at better-stocked stores.
• Online: every style from everyday Kikkoman to premium naturally aged shoyu is available via Amazon and Asian grocers.
• Make your own: possible but a months-long koji-and-ferment project; buying a naturally brewed bottle is far more practical.