Shoyu

Shoyu, or soy sauce, is a salty, savory liquid seasoning used widely in East Asian cuisine. The term shoyu is the Japanese word for soy sauce, itself derived from older Chinese jiangyou. Traditional shoyu is brewed through a fermentation process that uses koji mold to saccharify the starch in soybeans and grain (often wheat), followed by salt brine and long aging. The result is a complex, umami-rich liquid. Cheaper varieties are produced by acid hydrolysis of soy protein, producing a quicker, less nuanced product.

In Japan, common varieties include koikuchi (the dark, full-flavored and most prevalent style), usukuchi (a lighter color but typically higher in salt), and tamari (thicker and often wheat-free, with a deeper, smoother flavor). Outside Japan, soy sauces are labeled by color or regional style, and many blend different production methods. Tamari is often marketed as gluten-free, but brands vary in wheat content, so label checks are advised.

Uses for shoyu include seasoning, marinades, dipping sauces, and as a base for sauces and dressings. It provides a rich umami and saltiness that enhances meat, fish, vegetables, and noodle dishes. Storage should be in a cool, dark place; refrigerating after opening helps preserve flavor, and shelf life is typically measured in months to years depending on the product and additives. Shoyu remains a cornerstone condiment in many cuisines for its depth and versatility.