Miso Soup

The simplicity of miso soup belies its significance to Japanese cuisine, where it is a common course for breakfast, lunch, or dinner. It is ubiquitous on Japanese restaurant menus here in the United States, but miso soup is so uncomplicated to prepare that any home cook can make it. Variations are numerous, from the type of miso to the addition of vegetables, such as mushrooms or spinach, or other ingredients, such as tofu. Miso, or fermented soybean paste, is a staple of Japanese cooking. Depending on the amount of salt and koji (the mold used in the fermentation process) used, miso varies in color, flavor, and texture. Lighter versions, such as the white miso called for here, have a mild flavor and lower salt content; they are best reserved for delicate soups and sauces. The pronounced flavor of darker varieties (which include reddish-brown and dark-brown pastes) is better for more robust dishes. Shinshu miso, an all-purpose paste with a golden color and salty but mellow taste, would be a fine substitute for the white miso in this recipe. Wakame is another type of seaweed widely used in Japanese cookery, most often in soups and simmered dishes. It is available fresh or dried; to rehydrate dried wakame, soak in warm water for 20 minutes and drain before using.