Last January I had the opportunity to watch Portland chef Mike Wiley make some mostly-Maine koji. Koji has been a culinary mainstay across Asia for centuries where it’s used to make miso, sake and soy sauce. But only recently have Western chefs begun to recognize its transformative powers to cure foods or season them at the last minute.

“Koji is an enzymatic action hero,” Wiley said, gushing about its role in elevating a simple carrot salad he serves and being the umami bomb in his favorite fermented hot sauce.

Wiley, co-owner of the Big Tree Hospitality restaurant group which includes Hugo’s, Eventide and Honey Paw in Portland, is a koji convert. At the 2020 Chef’s Summit sponsored by the quasi-public marketing organization Taste Maine’s Future and hosted at O’Maine Studios in Portland, he made two types of koji by mixing aspergillus oryzae mold with Maine-grown black pearl barley, then with Marfax beans. He told the audience of chefs and food writers he hopes to eventually replace the 300 pounds of rice-based koji he buys annually for use in his restaurants with these homemade versions.

In long hotel pans, Wiley mixes the soaked, then steamed local grains he buys from Maine Grains in Skowhegan with koji granules he buys online. He slides the pans into a waist-high, commercial stainless-steel kitchen rack fitted with a snug plastic cover. With the help of a humidifier, a space heater and a couple of temperature controllers, he maintains the right conditions (85 degrees Fahrenheit and 75 percent relative humidity) for the spores to multiply over a 24-hour period to form a spongy, white blanket over the substrate.

He folds that mold back into the barley or beans and repeats the process for several days so the mold continues to feed on the grains or beans, breaking them down until the carbohydrates transform into sugars and produce glutamate, the substance that translates on the tongue as the magical ‘fifth flavor,’ umami. He says when this fermentation is done right, it smells faintly like yeasty bread. Done wrong, the mold dies.

During the demonstration, Wiley pulled out a jar of shio koji – a mixture of salt, water and koji – which he said is the easiest way for home cooks to add koji to whatever they’re cooking.

Koji is indeed a cool product made from a cool process. But when I heard Wiley speak in January, I could not fathom how even the most adventurous green-minded home cooks who read this column would have either the time or the inclination to acquire the gear needed to make it. Now that I’m cooped up at home thanks to the coronavirus, it seems slightly more plausible. But while I have not yet let my fingers do the walking around the internet to collect the required gear, I did reach out to Nicholas Repenning – who operates Go-En Fermented Foods in Whitefield with his wife, Mika; she is is Japanese. Together, they handcraft small batches of a variety of Japanese fermented foods including koji, miso and amazake, a traditional Japanese drink made of fermented rice.

A jar of shio koji, an Asian seasoning that is finding favor among western chefs. Shawn Patrick Ouellette/Staff Photographer

You can find Go-en miso in the refrigerated cases of many independent grocers and health food markets in Maine. But the only place to buy Go-En shio koji are at the couple’s booth at the Saturday farmers markets in Brunswick (at Fort Andross in winter and Crystal Springs Farm in summer) because not many home cooks “understand just how amazing the stuff is yet,” Repenning said.

But they should. “Shio koji’s got a somewhat sweet and mild salty taste itself, but the best thing it does is bring out the flavors of anything you add it to,” he said. Anywhere you might sprinkle a bit of salt, sprinkle two to three times as much shio koji in its place. Repenning suggests doing a side-by-side taste test of one egg scrambled with salt and one scrambled with shio koji as an easy way to taste the variation in flavor yourself. Other ways to see if shio koji can anchor your cuisine in umami include adding it to sautéed winter greens, beans, guacamole (helps to keep it green!) or homemade salad dressing. You can find non-local brands of shio koji in most Asian grocery stores.

If you’ve got more time on your hands, use shio koji as a short (30-minute) marinade for mushrooms or a 24-hour marinade for chicken, and the result will be more tender, more meaty plates of food. You do, though, need to keep a close eye on any shio-koji-marinated food when cooking it, as the increased sugars generated by the enzymes in the marinade means the food will burn faster than it otherwise would.

“We’re on the cusp of shio koji taking off. We could be looking at the seasoning of the year right here in this jar,”  Repenning said. Ride the koji wave and have some delicious fun.

CHRISTINE BURNS RUDALEVIGE is a food writer, recipe developer and tester, and cooking teacher in Brunswick, and the author of “Green Plate Special,” a cookbook from Islandport based on these columns. She can be contacted at [email protected]

Shio Koji Marinated Chicken Wings
Serves 2 as a meal, 4 as an appetizer

1/2 cup shio koji
2 tablespoons grated ginger root
1 tablespoon grated garlic
2 tablespoons soy sauce
1 tablespoon sambal oelek
2 pounds chicken wings
Vegetable oil
Lime wedges

Combine the shio koji, ginger, garlic, soy sauce and sambal oelek in a measuring cup.

Arrange the chicken wings snugly in a single layer in a non-reactive container. Pour the marinade over the chicken. Toss so the wings are coated on both sides. Cover and place in the refrigerator for at least 3 but up to 24 hours.

Preheat the oven to 350 degrees. Coat a baking sheet with vegetable oil. Transfer the wings to the prepared pan. Arrange them in a single layer. Discard the marinade. Bake the chicken for 15 minutes. Turn the wings over. Cook until the wings are coppery brown, 5-7 minutes more.

Serve the wings hot with lime wedges and plenty of cloth napkins.


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