Why This Recipe Works
by Tim Chin
Shio koji is a traditional use of koji, the ancient mold that gives us soy sauce, miso, fermented bean paste, and sake. It is made by combining rice koji (cooked rice that has been inoculated with koji spores and then dried), salt, and water and letting the mixture ferment for about a week, during which time it develops a sweet, fruity, slightly funky aroma. Shio koji is primarily used as a marinade. Because it is rich in protease enzymes (which break down proteins) and amylase enzymes (which break down starches), it can transform many foods. In our Koji Fried Chicken, it turns the chicken incredibly savory and tender. In our tests on fish, we found that shio koji firmed and gently cured the filets.