“I make miso in my hall closet, and so can you.”
By Nora Landis-Shack
When you first walk into my apartment, you probably wouldn’t suspect that in the small hall closet live several pounds of homemade miso. It may not seem wise to invite bacteria, spores, and slowly aging food here, but making miso in my hall closet is an easy, safe, and rewarding way to explore new flavors while expanding my culinary creativity, one that you can access too.
At its most basic, miso is a fermented paste made from soybeans, koji (rice or grain inoculated with a specific mold called aspergillus oryzae), and salt. The beans are cooked, mashed, and cooled before koji and salt are added (koji cannot survive above 140 degrees Fahrenheit). The koji produces powerful enzymes that break down the protein and starches in the mash, turning them into amino acids and simple sugars. It’s packed with complex flavors, richness, and versatility that translates to more than just soup, lending a savory roundness to baked goods and a subtle sweetness to meat dishes.
From Traveling Bean Pastes to Modern Miso
I made my first miso five years ago after diving into Sandor Katz’s The Art of Fermentation, widely considered to be a sort of fermentation bible. Katz provides a wealth of context and information on nearly every fermented product under the sun, with a chapter entirely devoted to the fermentation of beans, seeds, and nuts, including soybeans. He notes that many cultures use fermented bean pastes in their cooking, such as Chinese dòu bàn jiàng, Korean doenjang, and, of course, Japanese miso.
The Noma Guide to Fermentation, another go-to resource for aspiring miso makers, notes that the history of miso is as complex as the range of products we have available today. The earliest occurrence of soybeans goes back over 7500 years ago in northern China. As soybean cultivation evolved, fermentation became key to harnessing the legume’s full nutritional and flavor potential. This resulted in the creation of jiangs, fermented bean pastes that are foundational to many of today’s staple ingredients like soy, hoisin, and oyster sauces. These jiangs made their way to Japan in the sixth century via Chinese Buddhist monks, eventually leading to the birth of Japanese miso. Over the centuries, as miso-making became more specialized, new technologies and approaches further expanded the possibilities of miso variations. From the strain of aspergillus and the type of grain used to inoculate the spores to the mash, salt content, and aging time, any of these variables can be adjusted to create one-of-a-kind misos.
How to Make Miso at Home
While soybeans are traditional, misos can be made from any combination of legumes, starch, and vegetables and the appropriate amounts of koji, salt, and time. To successfully experiment with miso at home, you need a good base recipe, clean utensils, a calculator, a scale, and lots of patience, as the aging process can take anywhere from several weeks to years. But once you get the hang of the basics, you’re only as limited as your imagination.
Two key elements to successful miso-making are salt and moisture content. The salt prevents the growth of unwanted microbes and generally falls between 5 to 12 percent of the total weight of your other ingredients. As you grow more confident in the art of making miso, you may try out different salt ratios depending on your chosen flavors. For example, I recently started an apple and sage miso that uses 12% salt, on the higher end of the spectrum, to counterbalance the sugars and moisture in the apples and prevent spoilage. Moisture content in miso can be harder to gauge, but the Noma Guide offers a helpful tip: if you clench a fistful of the mixture, it should form a dense ball without oozing or crumbling.
While I love classic soybean miso, my favorites are the ones that move beyond tradition. Currently, I’m enjoying a sourdough miso that is funky and surprisingly sweet, excellent whipped into butter or spread generously on toast. In another corner of the closet sits a rich Norwegian rye miso salvaged from a failed bread experiment that is evocative of dark chocolate and an absolute delight in baked goods. There’s also coffee miso—a product of too many beans and curiosity— that’s only a month old but already bright and full of umami. I’ve felt myself grow as a cook with each of these culinary excursions into the limitless world of miso, which has quietly become one of the most important and bountiful ingredients in my kitchen.
A Note About Safety
Making miso does require working with mold, albeit the good and delicious kind. That said, a general rule in the fermentation community is “when in doubt, throw it out.” Strange odors and brightly colored mold mean you’ll need to start over.
BASIC MISO RECIPE
The following recipe is adapted from the Art of Fermentation. While this recipe uses a 1:1 ratio of mash to koji, you can also experiment with a 2:1 ratio. The latter option will require a longer fermentation time and more salt, resulting in what’s called a salty miso, as opposed to a sweet miso.
Makes 1 gallon
Special equipment: kitchen scale, 1 gallon-sized jar
Ingredients
2 lbs (~1 kg) soybeans or other legumes (see notes), soaked overnight
2 lbs / (~1 kg) koji (see notes)
5 -12% salt (see recipe)
Instructions
Prepare your beans by soaking overnight.
The next day, clean the jar with hot soapy water, rinse, and dry well.
Drain and cook the soybeans in fresh water until they are soft and easy to mash with a fork. You can do this on the stove or using a pressure cooker.
Once the beans are cooked, drain, reserving the liquid. Allow the beans to cool to at least 140℉ or lower.
Set a large heat-proof bowl on your kitchen scale and tare the weight.
Add the beans and koji to the bowl, making note of the total weight of your ingredients. Remove bowl from the scale.
Calculate the desired percentage of salt and weigh it out using a separate bowl. For example, if you have 2000 grams of mash and are going for an 8% salt ratio, you would use 160 grams of salt.
Use a little of the bean cooking liquid to dissolve the salt, then add to the mash. Add a little liquid as needed to get the miso to the correct consistency, which should be thick enough to hold its shape when squeezed in your hands.
Pack the miso into the jar, packing it down to eliminate any air bubbles that will result in spoilage. Sprinkle a thin layer of salt over the surface of the miso.
Weigh down the miso by using ceramic weights, a small plate, or by laying a piece of cheesecloth over the surface, topped with a heavy ziplock bag filled with water. Weighing down the miso helps keep air out and prevent spoilage, while also allowing tamari, an umami-rich liquid byproduct of miso making, to develop on the surface.
Place your miso in a dark and dry place with a relatively consistent room temperature. The warmer the temperature, the faster the miso will ferment. Allow to ferment for anywhere from 2 months to several years, checking periodically for mold and to taste for flavor. When you like the flavor of the miso, you can decant into jars and store in your fridge to halt the fermentation process.
Notes:
The soybeans can be swapped for a mix of different legumes, vegetables, starches, and flavorings. People have made misos from chickpeas, squash, and even peanuts. I have found that it’s generally helpful to have at least 50% of the mash be a starch or legume of some kind to form a solid base, with the other 50% open to experimentation.
You can typically find koji in a Japanese specialty store or Asian grocery store. I really like Cold Mountain Dry Rice Koji. If you purchase koji online, do it through a trusted resource, such as Cultures for Health. You can also explore making your own koji.
SOURDOUGH MISO
This is a sweet miso with the added funk of sourdough. You can use any kind of sourdough bread you like.
Makes about 1 gallon
Ingredients
1 lb (500 g) soybeans, soaked overnight
450 g sourdough bread, cut into cubes
2 lbs (~1 kg) of koji
120 g salt
Instructions
Prepare your beans by soaking overnight.
The next day, clean your jar with hot soapy water, then rinse and dry well.
Drain and cook the soybeans in fresh water until they are soft and easy to mash with a fork. You can do this on the stove or using a pressure cooker.
Once the beans are cooked, drain, reserving the liquid.
Using the liquid, soak the sourdough bread until it is soft and crumbly. Weigh the bread mash to ensure it totals 500 grams.
Allow the beans and soaked bread to cool to at least 140℉ or lower.
Set a large heatproof bowl on your kitchen scale and tare the weight.
Add the beans, sourdough mash, and koji to the bowl, making note of the total weight of your ingredients. Remove bowl from the scale.
Weigh out the salt and dissolve with a little more bean cooking liquid, then add to the mash. Add a little liquid as needed to get the miso to the correct consistency, which should be thick enough to hold its shape when squeezed in your hands.
Pack the miso into the jar, packing it down to eliminate any air bubbles. Sprinkle a thin layer of salt over the surface of the miso.
Weigh the miso down, and store in a dark, dry place for at least two months, after which you can start tasting and evaluating if you’d like to keep the ferment going longer.
When you like the flavor of the miso, decant into jars and store in your fridge to halt the fermentation process.
OTHER VARIATIONS
These variations are merely suggestions - once you get the hang of making miso and nail your ratios, feel free to experiment!
Black bean, chili, and cocoa
Farro and pepita
Barley and cinnamon
Apple and sage
White bean, butternut squash, and rosemary
Jasmine and parsnip
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Nora Landis-Shack is a first-semester student in the Food Studies program, with almost a decade of work experience in communications and partnership development at public health nonprofits, most recently at Hot Bread Kitchen. Nora currently serves on the advisory board for the Queer Food Foundation.