How to make Shio Koji – the Fermented Rice Marinade for poultry, meat and fish

The Chef’s notebook:
“Make Shio Koji to marinate poultry, meat, fish or use it to make bread”

Koji Makes Anything Taste Better & Shio Koji is the secret Fermented Rice Marinade that Chefs choose to marinate poultry, meat, and seafood. As with other kin-derived ingredients like soy sauce and miso, shio koji lends savory depth to foods it comes into contact with, thanks to protease enzymes that break down proteins into amino acids, which we perceive as umami.

What is Koji?

The traditional definition of koji is a specific ancient mold (aspergillus oryzae) inoculated cooked grain (typically rice or barley) and/or soybean that’s used as a starter for Japanese ferments like shoyu, miso, sake, and mirin.

Koji, or dried rice grains cultured with aspergillus oryzae, make any and all foods taste like hyper-version of themselves. Imagine you could level up the taste of every dish you make, naturally. That’s exactly what filamentous fungus koji does: As spores grow (a friendly, white, fluffy mold), they break sugars and proteins down into their very basic forms, making them more readily available to our tongues.

What does this mean? Steaks casually seasoned with the stuff will sport an unprecedented savoriness; prosciutto will be completely cured in a matter of months not years; and bread becomes intoxicatingly yeasty — all without the addition of salt, fat, sugar, or time.

How to make Shio Koji

Steps for making Shio Koji

• Combine rice koji with kosher salt in a lidded container
• Stir in water until the salt has dissolved
• The general ratio for shio koji is 5:4:1 by weight of water to grain koji to salt (the ratio is adjusted slightly in the attached recipe to accommodate volumetric measurements)
• Once the mixture is well-combined and the salt is dissolved, pop the lid on your container and find an out-of-the-way spot in your home to ferment it at room temperature
• Stir the mixture once per day: This ensures that the rice grains are being evenly coated with the liquid, which will take on an increasingly milky color as well as a sweet and funky aroma
• After a week, the mixture will thicken to a porridge-like consistency and will smell fruity and pleasantly fermented. Depending on the time of year and the temperature in your home, this fermentation process might take a day or two longer, but it will be good to go between seven and ten days.
• At this point, pop the marinade in the fridge and store it there until you’re ready to use it