With few ingredients and a quick and simple preparation, miso soup is an inexpensive, flexible and ubiquitous staple dish at Japanese mealtimes.
Miso is an ages-old seasoning paste made from fermenting soybeans with a fungus, koji (Aspergillus oryzae), along with salt and often grains or other additives. It is used in a variety of preparations and methods, most commonly forming the basis of this nutritious, protein-rich soup. Several factors can affect its flavor and appearance, but generally miso is divided by color into white (shiromiso) and red (akamiso).
The other half of authentic miso soup is dashi, a broth made from reconstituting dried fish shavings known as katsuobushi. The flakey, paper-thin katsuobushi (also called bonito) is usually made from dried and smoked skipjack tuna (Katsuwonus pelamis), although other species of tuna, sardines, mackerel or even shiitake mushrooms can be used. Identified as one source of umami, the fifth taste, katsuobushi dissolves away easily in hot liquid for a mild yet flavorful seafood stock.
Only the miso and dashi are essential for this soup, with further ingredients added to reflect the seasons and availability. Tofu is a popular option but other meats or seafood can be gently poached in the dashi as well as mushrooms, seaweed (wakame) or root vegetables such as potato or daikon. Care is usually taken not to boil the miso itself as that can alter its flavor and kill the active cultures it contains, reducing any health benefits.
True miso soup (misoshiru) is little more than dashi and miso, yet it lends itself to almost infinite variations. Western recipes often mix the dashi using vegetable broth or even chicken stock instead of plain water, and a Filipino version includes tamarind for a distinct sour flavor.
Serve miso soup as an appetizer to a multi-course Asian dinner or sushi, or pair with steamed rice for a traditional Japanese breakfast.
2 t (10 g) dashi
4 green onions
2 T miso
14-oz firm tofu
1 Bring 8 c water to a bare simmer in a pot. Add the dashi and simmer, uncovered, for 10 min (do not boil).
2 Temper the miso with the dashi water, then add back to the broth. Stir until incorporated.
3 Finely chop the onions and dice the tofu. Add to the soup when ready to serve.