Alive with flavor

Making the fermented Japanese flavoring miso from scratch

Tamayo Johnson (left) and Keiko Tokuda mix sea salt and koji to make miso.

Tamayo Johnson (left) and Keiko Tokuda mix sea salt and koji to make miso.

Keiko Tokuda wasn’t teaching me how to make soup. I was invited to the home of the Chico State/Butte College Japanese-language instructor to learn how to make actual miso—the nutritious, salty-sweet, caramel-colored paste that goes into delicious miso soup—from scratch. And I was thrilled to be joining her and her friend Tamayo Johnson for the intimate tutorial.

Tokuda—who gave a lecture on miso at last fall’s Far East Fusion event at Chico State—has been making her own miso for six years.

“I was buying it, but it gets so expensive,” Tokuda said. “So I decided to make it. It’s real easy.”

When I arrived at Tokuda’s house, she had already cooked the 500 grams of dried soybeans necessary for my batch of miso in a pressure cooker until they were soft (after first soaking them for eight hours). We then ground the beans to a paste in a food processor while they were still warm, adding a little liquid from the cooked-bean water as necessary to make the paste smooth.

The three ingredients that go into miso– soybeans (ground into paste), sea salt and koji.

Miso can also be made from chickpeas (garbanzo beans) or adzuki beans (chickpea miso is Tokuda’s favorite), but soybean miso is more traditional.

Next, I mixed with my hands 500 grams (17 ounces) of koji—dry rice kernels impregnated with a fermentation-promoting fungus called Aspergillus oryzae—with 250 grams (8.5 ounces) of sea salt in a metal bowl. Koji can be purchased online at www.coldmountainmiso.com or at Japanese markets in major cities like Sacramento or San Francisco.

There are only three ingredients in miso, with the standard ratio of soybeans to koji to salt being 2:2:1.

“In Kyoto, they have the sweetest miso—kyo miso,” Tokuda said. The kyo-miso variety is made with three times as much koji as soybeans. “More koji makes it sweeter, and makes it have a shorter fermentation, but a shorter shelf life.”

Kyo miso takes only three to four months to mature, whereas the standard miso we were making will take about six months to a year to mature, though it could be ready to be eaten in as early as four months. Miso is not mature yet if you can taste the salt separately from the other ingredients, Tokuda advised. It must taste “mixed-up.”

It is best to make miso “in cold temperatures,” said Tokuda, “not in Chico summer, because the first month [of fermentation], it is susceptible to mold.” If it doesn’t get a “colorful” mold in the first month, it will be fine. If it does, “throw it in the compost and start over!” A white mold, like that on soft cheese, is OK.

After mixing the soybean mash with the koji-salt mixture with my hands (using hands instead of utensils is essential to give each person’s miso a distinct character), we made baseball-sized balls from the resulting mixture and then threw them forcefully into the plastic container I had brought for my miso. (Tokuda uses large stoneware crocks for her miso, but says plastic works just fine.) The force is needed to get air out of the mixture, to help along the anaerobic fermentation process it will undergo.

After throwing the miso balls into my container, which I sterilized by wiping it out with vodka, I packed them down very tightly with my fists to release as much air as possible, before lining the edge of the mixture with sea salt and covering it with wax paper. At home, I weighted the mixture down as instructed with two clean bricks and stored it in a cool place—a shelf in my pantry ("not a fridge"). Tokuda also uses bricks, as well as rocks and heavy wooden disks (made from wood reclaimed from the old Hooker Oak), to put pressure on her fermenting miso.

“Check it in a month,” Tokuda said. First pour off the bit of delicious golden liquid—the tamari—that rises to the top periodically and save it as a seasoning for cooked rice. “The salt goes to the bottom, so mix [the miso] up every month with your hands. When you like the taste of your miso, put it in the fridge.”