Choosing soy sauce based on its manufacturing process significantly impacts the aroma, taste, and appearance of your dishes. Three common types—nama-shoyu (unpasteurized soy sauce), ki-joyu (standard brewed soy sauce), and nikiri-shoyu (cooked soy sauce)—each have distinct characteristics and uses. Understanding these differences will help you select the right soy sauce for enhancing the natural taste of ingredients and achieving the perfect balance in your dishes.
Nama-shoyu (なま醤油)
Nama-shoyu is an unpasteurized soy sauce characterized by its rich aroma and flavor. It skips the typical pasteurization process (sterilization of microorganisms) used in regular soy sauce, instead relying on precise filtration to remove yeast and microorganisms, ensuring freshness and safety. Because it is unheated, applying heat during cooking further enhances its aroma, allowing you to enjoy a vibrant color that highlights the natural hues and flavors of ingredients, along with a mellow, smooth umami taste.
Due to its living microbial nature, it maintains freshness at room temperature when stored in a sealed double-layered bottle that prevents exposure to air. Refrigeration after opening is sometimes recommended. It is ideal for sashimi, cold dishes, or as a finishing soy sauce, where enhancing the aroma and color of ingredients is desired.
Incidentally, unpasteurized pressed soy sauce is sometimes called “kiage-shoyu.” Since it hasn’t undergone heat sterilization or filtration, it’s soy sauce that retains microorganisms like lactic acid bacteria and yeast.
Ki-joyu (生醤油)
Ki-joyu is originally a term from the culinary industry, referring to soy sauce made solely from “soybeans, wheat, and salt,” which has undergone pasteurization. Pasteurization is the process of heating raw soy sauce to inactivate microorganisms and enzymes, thereby adjusting its aroma and flavor. This heating deepens the color, creates the characteristic savory aroma and taste of soy sauce, and produces a mellow overall impression.
Under JAS regulations, the only permitted additive is salt. Products labeled with only “soybeans, wheat, salt” on their ingredient list are ki-joyu. This signifies a pure soy sauce with no additional seasoning, suitable for a wide range of dishes like simmered and grilled foods. It also boasts a longer shelf life and more stable flavor compared to nama-shoyu. For sushi, ki-joyu is preferred over nikiri-shoyu when the soy sauce’s inherent, wonderful aroma is prioritized.
Nikiri-shoyu is a seasoned liquid made by adding mirin, sake, and sometimes dashi such as bonito broth to soy sauce, then heating it to evaporate the alcohol. “Nikiri” refers to the cooking technique of heating mirin or sake to evaporate its alcohol content, said to have originated with Edo-period street stall sushi. Evaporating the alcohol softens the sharpness of the soy sauce, enhancing the umami without overpowering the flavor of the seafood toppings. Furthermore, adding dashi incorporates its umami components, creating a deeper, more complex flavor. In sushi restaurants, it is used for all types of seafood sushi toppings.
Summary:
Nama-shoyu is best used for raw or cold dishes, as it brings out the natural color and aroma of the ingredients. Ki-joyu is a versatile, pure soy sauce that works well in cooked dishes when the soy sauce’s own flavor is desired. Nikiri-shoyu is a seasoned, umami-rich soy sauce, perfect for enhancing the taste of all types of sushi toppings.