In daily cooking, soy sauce is indispensable for enhancing flavor, adding color, and providing nutrition. However, people often use one bottle of soy sauce for everything—from stir-frying and cold dishes to making soups and for dipping. This is not actually the best practice. Zuo Baoqi, Director of the Science and Technology Department of the China Condiment Association, explains that choosing soy sauce requires reading the label.
Fermented soy sauce is purer. From the ingredient list, you can see if the main ingredients are soybeans or defatted soybeans, and wheat or bran. The most important thing is to check whether the label specifies "fermented" or "blended" soy sauce. Fermented soy sauce contains no other additives; blended soy sauce is made primarily from fermented soy sauce with added acid-hydrolyzed vegetable protein seasoning and food additives. In comparison, fermented soy sauce has a purer grain composition.
The higher the grade, the more umami. When reading the label, also check the grade. The umami of soy sauce depends on the content of amino acid nitrogen. Generally, the higher the amino acid nitrogen, the higher the grade of the soy sauce and the more delicious it is. According to China's current standards, soy sauce is divided into four grades. However, this does not mean that a soy sauce with higher amino acid nitrogen is necessarily better. This is because blended soy sauce can also have a high amino acid nitrogen content, or some unscrupulous suppliers may add a large amount of flavor enhancers, resulting in high amino acid nitrogen, which does not equate to a high-quality soy sauce.
Light soy sauce for stir-frying, dark soy sauce for coloring. "Light and dark soy sauce are mainly distinguished by their production process," Zuo Baoqi explains. Light soy sauce has a lighter, reddish-brown color and a saltier taste, making it suitable for both stir-frying and making soups. Dark soy sauce is made by taking light soy sauce and sun-drying it for another 2-3 months, followed by sedimentation and filtration. Its quality is richer than light soy sauce, making it suitable for coloring food, such as in braised dishes.
Cooking soy sauce should not be eaten raw. "You shouldn't use the same soy sauce for both stir-frying and cold dishes," Zuo Baoqi points out. China's current "Fermented Soy Sauce" standard requires soy sauce to be labeled as either "table soy sauce" or "cooking soy sauce," as their sanitation indicators and bacterial counts differ. Cooking soy sauce can be either light or dark and generally should not be eaten raw because even qualified cooking soy sauce may contain a small amount of bacteria and requires heating before consumption. Table soy sauce is usually light soy sauce, with a total bacterial count of less than or equal to 30,000 per milliliter, making it safe for dipping and in cold dishes without harming health. "However, a new soy sauce standard is currently being revised, which will raise the standard for cooking soy sauce to a level where it can be eaten raw," Zuo Baoqi says. For now, it's best to have three types at home: cooking light soy sauce, cooking dark soy sauce, and table soy sauce.