Miso soup (misoshiru 味噌汁) is one of the fundamental staples of Japanese cuisine. For many older or more traditionally-minded Japanese people, a meal isn’t complete without rice and miso soup. Fortunately, miso soup is very easy to make.

The ingredients are very simple: dashi, miso, and garnishes.

Dashi: for ordinary home-brew miso soup, the finest dashi is not really necessary, but the powdered stuff is really so inferior that it will not give acceptable results — sort of like comparing mediocre canned soup to decent homemade. Dashi made from the teabag-like packets will be perfectly reasonable.

Miso: There are many kinds of miso, with a wide range of flavors. They are often combined when making miso soup. A common Tokyo-style mixture would include roughly 50/50 proportions of red (aka) miso and sweet white (shiro) miso. As a rule, avoid miso that has noticeable chunks, i.e. coarse styles like kōji-miso best used for other applications. For most miso soup, a miso with a strong flavor of sake lees will impart a peculiar flavor, although this may be desirable in certain heavy winter soups (see below).

Garnishes: Purists generally insist on three different garnishes, though there is no absolute rule about this. Roughly speaking, one garnish is pre-prepared, one is cooked gently in the soup, and one is used essentially raw. The three most common are wakame seaweed (prepared in advance), soft/silken tofu (cooked in the soup), and thin negi or scallion rings (near-raw).

Appropriate replacements for the pre-prepared garnish include almost any sort of mild, well-blanched vegetable, especially root vegetables such as daikon, carrot, salad turnip (kabu), or potato. Sometimes one encounters thin slices of pork or chicken, poached or stir-fried.

Tofu is extremely popular, but may be replaced with anything that can be cooked by simply warming it in the soup, such as konnyaku (蒟蒻 / こんにゃく). It is important that this garnish should not flavor the soup, but rather gain flavor from it.

Raw garnishes are rarely precisely so: they are added when the soup is at peak heat and allowed to stand in it for a minute or so, softening and infusing a little flavor. Appropriate ingredients here include any kind of mild allium (negi, scallion, onion, shallot, leek); turnip, daikon, watercress, parsley, or mitsuba stems cut in 1"-2" lengths, blanched and shocked if large and firm; curls of yuzu or other citrus peel.

Making Miso Soup
Warm the dashi to a bare simmer. Meanwhile, pre-prepare your garnishes as appropriate. Wakame should be prepared according to package directions, as the different brands vary somewhat; be aware that it swells enormously, so be sparing with it.

When the dashi is simmering, add the ingredient to be cooked in the soup (e.g. tofu) and the pre-cooked ingredient (e.g. wakame), and continue simmering gently for a few minutes, until heated through.

At this point there are several methods for adding miso:
  1. Drop a generous tablespoon or so of miso, in whatever mixture you wish, into a small basket strainer, and lower this into the simmering soup. With a spoon, chopsticks, or small whisk, stir the miso vigorously in the liquid until it dissolves completely. Remove the strainer, lifting out any firm, indissoluble chunks of the miso.
  2. Place the miso in a small bowl and add a generous ladleful or two of the dashi. Beat or stir until smooth, as for tempering eggs, then pour the mixture back into the pot through a strainer.
  3. Place the miso directly in the soup and stir until fully dissolved. This will leave any firm chunks in the soup, so if you are using a miso that is not completely smooth you will have a rather coarse, rustic product — which may be desirable. Note that this method tends to break up chunks of tofu, making them less attractive and more difficult to eat with chopsticks.
Once the miso has been added, it is essential that the soup should not come near a boil. Over-cooked miso has a very different flavor that is not desirable in miso soup. Allow the soup to cook very gently for a minute, add the raw ingredient (e.g. negi rings), and continue cooking gently for a minute or two more. Remove from heat.

Miso soup is normally served hot but not scalding; there are, however, high-end gourmets who argue that it should be served at near-boiling temperature. It should be served in individual wooden or lacquer bowls that can be picked up easily in one hand without burning oneself. Japanese miso soup bowls have a tall rim on the bottom, against which one rests one’s fingertips while drinking. Drink the soup, and pick the pieces out with chopsticks. Spoons are not usually used.

Butajiru/Tonjiru ( 豚汁,とん汁)
This hearty winter soup will considerably change the way you think about the ubiquitous miso soup. Stir-fry together some sliced pork with any or all of the following: carrot, potato, turnip, daikon, onion, 1½" lengths of negi or scallion, mushrooms, taro, gobo (burdock), konnyaku. You may stir-fry plain in a little oil, or season the partly-cooked mixture with a dash of sake. Add dashi and heat to a bare simmer. Add tofu, if desired, but remember that you cannot stir much after this point. When the soup is hot, add miso in the usual way; you may wish to add a little more than usual, or to use a stronger or coarser style of miso, as the flavor does get somewhat overpowered. Garnish with sliced raw negi or scallion and serve hot.