Making My Own Miso

Smashed beans, or how I made my own miso.

Our first year here in Japan was full of food-making adventures: umeboshi, sashimi, umeshu, and kimchi. It was all good fun and led to a whole variety of other experiments. We now have what we call a Shu Closet, where we keep the many jars of fruit shus I've made over the years plus an occasional brandy concoction and umehachimitsu, a lovely non-alcoholic beverage perfect hot or cold.

Yet, the experiment that I've delayed out of a certain sense of intimidation is miso. A friend of the farmers stopped at the farm one day and offered a sample of some he'd made. It was chunky and yeasty smelling, and super delicious. It was amazing.

Daizu waiting to meet the koji and salt.

I'd been further motivated to try my own after interviewing Takashi Watanabe of Tozaiba and the One Bean Revolution. As he spoke about daizu (soy beans) and their importance in Japanese culture, I fell in love with that little bean. I began searching out heirloom varieties and products made with them. I hoped to try growing some of my own. I decided miso would be my next goal.

Flash forward four years, to a recent Earth Day Farmers Market I stopped at Yamamoto Farm's table as usual in search of their homemade mochi and miso. There to my pleasant surprise were bags of daizu and koji with salt. Without hesitation, I snapped them up and Yamamoto-san gave me detailed instructions on what to do. Giddy, I headed home with my loot and got to work.

Koji and salt simply waiting to meet the beans.

Basic Miso: The First Try
1 kilogram soy beans.
1 kilogram of koji-infused rice and salt

• Soak the beans. 

Yamamoto-san recommended soaking the beans for half a day, which I took to mean about four hours. After two hours, the beans had changed from their slightly rounded shape to a more, well, beany one. They'd also managed to soak up quite a bit of water, so I added some and let them loiter some more. By the end, they were quite easy to bite, although still in need of cooking.

• Boil the beans.

I drained off the soaking water, covered them with fresh water, and then set them to cook. Once the water started to boil, I turned the flame down for a steady simmer. I didn't want to burn them or cook them too fast. Yamamoto-san's advice was to cook the daizu until they easily squished between thumb and pinky finger. (Try it. It's hard to get good pressure even without a bean in between.) This translated into roughly two to two and a half hours for a seriously soft bean.

• Drain and smash.

I drained off the cooking liquid, but saved back a good-sized bowl per Sandor Katz's recommendation in Wild Fermentation: The Flavor, Nutrition, and Craft of Live-Culture Foods (Chelsea Green, 2003). This flavorful fluid can be added if the bean mash seems to dry. Once cooled, Katz also recommended mixing in some of the koji, too, to get the yeast rolling. I didn't do this since Yamamoto-san didn't mention it, but following Katz's advice would never be a bad thing.

For smashing, I used an antique potato masher I'd purchased at an antique store in my hometown. Originally destined to help make jam, it worked like a charm on the beans. The texture proved rather chunky, though. I like it that way, but others may desire something smoother. A food processor or more time with the hand masher would do the trick.

• Add the koji and salt.

I'll never forget opening that bag of koji. The smell that emerged was yeasty and wonderful, putting me in mind of my bread-making days in America or peeking at my mother's coffeecake dough as it magically rose under a dishtowel in a corner of the kitchen. Pure joy and a connection with so many parts of the past and this new culture is what I felt right then. Even if my miso fails, this moment alone was totally worth it.

Koji is the yeast that gets busy fermenting and turning the daizu into miso or rice into sake. Word has it that it also makes a mean pickle. Its most common form is as koji-infused rice, which is how Yamamoto Farm sold it. I simply filled a cup or two, poured it over the smashed beans, and started mixing it, literally, by hand.

Hand-mixing!

I chose this method because I remembered something Takashi Watanabe said when I first met him. He said that the maker's hands literally contributed salt and flavor to the miso, giving it a unique flavor. It was how people could really connect with their food. I also chose it because a metal tool would react with the salt, and my wooden spoon was in the dirty dishes.

As I worked the mixture in my hands I could feel the bits of beans that hadn't been completely smashed, and the grains of koji. It reminded me of kneading bread dough, a sort of meditative process that resulted in a warm feeling and a tasty treat to share with others.

• Salt the jar.

Katz recommends coating the bottom and sides of the miso container (a ceramic, glass or plastic bucket or jar) with salt to help the fermentation process. As it does with sauerkraut and umeboshi, the salt draws fluid out of the beans and creates a brine that flavors and preserves the miso.

• Place miso in jar and cover.

Once the jar was properly salted, I took great handfuls of the miso and placed it inside. I smashed it down tightly to remove any air bubbles and to make sure it would all fit. Once everything was in I put another layer of salt on the top and then added a weight. Yamamoto-san suggested a weight that was only ten-percent of the total amount. Katz doesn't suggest such a requirement. Both, however, do agree that the entire surface of the miso should be covered to ensure the best fermentation process.

• Wait.

My first miso, not perfect, but ready to ferment.

Once covered, I put the signature red lid on the jar, placed it in a thick bag for extra darkness, and left it to sit. Yamamoto-san and Katz both recommend a cool, dark place where the koji can work its magic. For now, ours is under the bathroom sink. Come summer, though, I'll have to transfer it to a friend's house that is cooler. In July, I'll check it and scrape off a layer of mold that will have formed on the top. Then in September, we'll start eating it!