Miso soup is deceptively simple. It contains just a handful of ingredients: fermented bean paste (a.k.a. miso), vegetables, and hot water or stock. Heck, you don't even have to use tofu (although if you do, make sure it's the right kind; more on that in a moment). That said, simple doesn't always mean foolproof. There are a handful of common mistakes folks make when simmering together miso soup at home. Avoid these pitfalls, and you'll be well on your way to becoming a miso master.
"You get what you pay for," explains Brad Leone, BA's test kitchen manager and miso soup enthusiast. With a soup that requires so few ingredients, the quality of each one really matters. We like South River Miso, which is made in Massachusetts and fermented in wooden barrels according to traditional Japanese technique. A little miso goes a long way, so don't be alarmed by the price tag on the good stuff—a jar of miso will last you well into cold-and-flu season.
Boxed or canned stock may be passable for the average chicken soup, but miso demands something special and a little more subtle. Leone likes to make his own dashi, an aromatic broth flavored with kombu, or dried seaweed. The vegetal, briny flavor of the seaweed enhances the funky, salty miso in a way that typical broth just can't.
The miso soup of your dreams. Photo: Alex Lau
"You've gotta use silken tofu," says Leone. Save the extra-firm for your stir-fries. Silken tofu, which has the consistency of a thick pudding, melts into the broth, giving it body and depth. There's just no substitute.
Adding veggies like carrots, turnips, or radishes to your miso soup? Don't sauté them. That cooking method requires fat, like oil or butter, which will give the soup a greasy texture. Instead, slice and chop the vegetables small and thin enough so that they'll cook rapidly with a quick boil in the broth. As for garnishes, like scallions, chopped spring onions, or chives, don't add those until just before serving. Otherwise, they'll wilt.
Miso is a fermented food, meaning it contains live, active cultures of bacteria—you know, like the good stuff that's also found in yogurt. Adding it to boiling water will kill the probiotics in the miso, nixing the health benefits it typically offers, like better digestive health. Wait until the soup has been taken off the heat and then stir or whisk in miso to taste. The paste-like texture will melt into the soup thanks to the residual heat of the stock. Slurp on.
Alaina Sullivan, a designer at BA recommends making a "miso slurry" before adding it to the stock. It will be lumpy, with large clumps of miso, if you skip this step. Says Sullivan, "Mix it with a bit of the warm broth and whisk it so that it dissolves fully, then pour it back into the warm broth. I usually do a ratio of 1 tablespoon of miso to 1 to 1½ cups water." As for white kind of miso to use? Both Leone and Sullivan like sweet white miso for a mellow-tasting soup. "Many restaurants use red misos," Sullivan says, adding that yellows are more earthy.
If you let your soup sit before serving, not only will it get cold, the miso will settle to the bottom. If this happens, not to worry: Says Sullivan: "A quick whirl with your chopsticks will stir it back up."