Soy sauce is the world's most consumed condiment after salt. Born in China over 2,500 years ago, it has spread across Asia and beyond, developing into dozens of regional varieties with radically different aromatic profiles. Understanding these differences transforms the way you cook.
Fermentation: the heart of the process
All authentic soy sauces share the same basic process: soybeans and wheat ferment under the action of the mould Aspergillus oryzae, salt and time. It is the duration of fermentation and the proportions of ingredients that define the final character. Long fermentation — several months to several years — develops hundreds of aromatic compounds through Maillard reactions and other complex chemical processes.
Light or dark: a fundamental distinction
Light soy sauce is saltier and more fluid. It seasons without colouring — ideal for marinades, dipping sauces and dishes where the colour of ingredients must be preserved. Dark soy sauce contains molasses or caramel: it is thicker, sweeter, less salty, and brings a deep mahogany colour to braises and lacquered meats.
The great regionals: Japan, China, Korea
Japanese shoyu (such as Kikkoman) is made with equal parts wheat and soy, giving a milder, more aromatic sauce. Japanese tamari is made exclusively from soy — without wheat — and is perfectly suited to those intolerant to gluten. Korean soy sauce (ganjang) is more complex, often fermented from dried soybean blocks. Each variety has its specific uses and cannot simply substitute for another.