Les Dames D’Escoffier held an all-day symposium recently for the first time since the pandemic. One of the workshops focused on Japanese fermentation; specifically, the complex relationships among sake, soy sauce, and koji. There were three styles of sake to taste, and a chance to make our own koji infusion. Remembering how intrigued I was with the koji demonstration at the Sakura Matsuri, I signed up for that workshop.
Although far less familiar in the West, koji has been the foundation of Japanese cuisine for centuries. It’s rice (or another starch) inoculated with the fungus Aspergillus oryzae, and it’s the basic ingredient for soy sauce, sake, miso, rice vinegar and many other products. Now koji has become the trendy plaything of chefs all over the world.
In their book The Noma Guide to Fermentation, René Redzepi and David Zilber describe koji as “indistinguishable from magic.” Now, I admit this reference to Clarke’s Law made me perk right up, and I paid even closer attention to the workshop’s presentations about sake and soy sauce production. Then, we got to make our own koji – or at least, start the process going.
We added salt, garlic, ginger, and water to the inoculated rice at each of our places. All we had to do after that was take them home, stir them every day for 10 days, and use the resulting ferment as we pleased. The workshop sponsor recommended coating chicken breasts and grilling them. My research resulted in several other possibilities.
I decided to marinate turkey thighs overnight, and then grill them. I used about two-thirds of the contents of my little jar for the marinade. The results were amazing, juicy and delicious, with a subtly altered taste and texture from any previous turkey I’ve had before. I can see using this technique for a Thanksgiving turkey breast and no worries about having it come out dry!
I used the remaining koji on a nice piece of white fish for my daughter and myself. I marinated the fish for only a few hours, but the results were still remarkably delicious. My daughter, who lived in Japan for several years, put it perfectly: “This fish tastes like Japan!”
She recognized, and appreciated, the characteristic strain of umami the koji had imparted to the fish. There was a little fish left, so I ate it over avocado toast for lunch the next day. Cold, it continued to be just as delectable as freshly roasted.
I’m going to be experimenting with this promising new technique for a while. Google tells me that koji-inoculated rice is available to order on the internet, and there is a Japanese grocery store in Rockville. Much umami ahead!
