Kombu is seaweed from the genus Laminaria, and it is an important part of Japanese cuisine. Kombu is also eaten in other parts of Asia as well; it can be found fresh, dried, pickled, and frozen in many Asian markets. There are a wide range of uses for kombu, and it is one of the more popular foods in Japan since it is so versatile and affordable, thanks to seaweed farming which makes it easy to cultivate and harvest kelp.

The exact type of kelp used in kombu varies. All of the parts of the plant are used, including the thick stalks and fronds or leaves. When harvested and dried naturally, kombu acquires a thin layer of white powder which some consumers believe is extremely flavorful. The plant also contains a high concentration of free glutamate, which creates the famous savory “fifth taste” in Japanese cuisine.

Pickled kombu is often served as a relish with a meal, or as a small started salad or snack. Many bars and tea houses offer bowls of pickled kombu to their guests, and it may be served on rice or alongside vegetables as well. Dried kombu frequently appears in mixes for dashi, a fundamental soup stock which is used in a great deal of Japanese cuisine. Flakes of dried fish or mushrooms may be added to dashi as well for additional texture; many people are familiar with dashi as the base for miso soup, a very popular Japanese food often offered at sushi restaurants in the West.

When dried properly and stored in a cool dry place, sheets of kombu will keep for an extended period of time. The fine white film which appears is entirely normal and in fact desired; the sheets of kombu should be gently wiped with a damp cloth before use. Pickled kombu can likewise be stored for long periods, although it needs to be refrigerated and used in a timely fashion after opening. It is also easy to make pickled kombu at home, for cooks who want to play with ingredients and spicing.

Since most cooks use their kombu shredded, some stores sell nalto kombu, which is preshredded kombu. Seaweed can also be purchased fresh in some parts of the world, although it does need to be used quickly because it has a short shelf life. Always wash fresh kombu before using it. As an alternative, some stores sell frozen kombu for consumers who want the fresh flavor and a longer shelf life.