Three in four Japanese people drink miso soup at least daily
Most of the miso Japan makes each year, more than 80 percent, ends up dissolved in soup, and about three quarters of the population has a bowl at least once a day. The recipe is simple, fermented soybean paste in stock, but the choice of paste changes everything.
Miso itself is a fermented seasoning: soybeans, salt and the mould Aspergillus oryzae, called kojikin in Japanese, sometimes with rice or barley added. Broadly it comes as red akamiso, white shiromiso or a blend called awase, plus regional styles such as Shinshu and Sendai. Time in the vat sets the tone. A short ferment gives the pale, sweetish white kind, while a long one produces the darker, deeper red. Around Tokyo the soup also goes by the name omiotsuke.
The base is dashi, most often brewed from dried baby sardines, kelp, shaved smoked bonito or dried shiitake, and kelp or mushroom versions make it vegetarian. When clams go in, cooks often skip the dashi entirely. Outside Japan, people sometimes dissolve miso in vegetable or chicken stock, and there is genuine disagreement over whether that still counts as miso soup. Along with clear suimono, it forms one of the two fundamental soup families in Japanese cooking and is the soup of the classic one-soup, three-dishes meal built around rice.
Ingredients follow the seasons and are chosen for contrast. Pungent negi is paired with mild tofu; wakame that floats is matched with potato that sinks. Winter bowls turn hearty with daikon, fried tofu and dark miso, while spring and summer favour cabbage, myoga or eggplant. Add pork and the dish becomes tonjiru, a lunch or dinner soup rather than a breakfast one. At breakfast, miso soup and white rice sit at the centre, the soup sipped straight from a lidded lacquer bowl with chopsticks for the solids.
One popular belief is simply wrong: heating miso does not wipe out its benefits by killing microbes, since the useful nutrients come from enzymes active while the paste is made. Japanese studies have linked habitual miso soup to lower blood pressure and a lower risk of some diseases, though these are associations from particular studies. The oddest preparation belongs to Awashima island off Niigata, where wappani is cooked by dropping hot stones into a cedar vessel of soup, fish and vegetables.
Source: Miso soup
