Koji, the Japanese name for a mold called Aspergillus oryzae, provides the fermentation power that makes soy sauce, miso, rice vinegar, and sake. First mentioned in China more than 2000 years ago, it’s been called the “national fungus” of Japan. Shio koji combines rice that’s been inoculated with koji, salt, and water, and it’s often used as a marinade since the abundant enzymes help break down both proteins and starches. It’s lightly sweet and salty flavor also makes food delicious.