Koji-Marinated Grilled Salmon

• Two 4-oz. salmon fillets
•  Kosher salt
• 2 Tbsp. ama koji or amazake

Koji is the fungus that grows on rice, barley, soybeans, and corn after it is inoculated with the fermentation culture Aspergillus oryzae. It resembles thin rice porridge and is full of enzymes that produce amino acids when they interact with protein. One of those amino acids, glutamate, is responsible for the taste we know as umami, which is present in miso and soy sauce and makes foods especially savory and flavorful. 

There are two types of koji used for cooking: ama koji and shio koji. Ama koji, which means “sweet koji,” has no salt, so you can control the seasoning yourself. It’s also more readily available in a less concentrated form known as amazake. In this simple recipe adapted from James Beard Award-winning chef Jonathon Sawyer and fermentation specialist Jeremy Umansky, ama koji is used to lightly cure salmon fillets before they hit the grill. It’s a great starter dish to introduce you to the powers of this pantry staple. 

Due to the enzymes found in the koji, the salmon will be extremely tender and buttery post-marinating. Because of this, Sawyer and Umansky recommend grilling to rare or medium-rare.