and tax from the Tōhoku Region. Its actual use is believed to be much earlier, most likely dating back to the Jōmon period, but as it easily decomposes, no archaeological evidence can be found. During the Muromachi period, a newly developed drying technique allowed kombu to be stored for more than a few days and kombu became an important export from the Tohoku area. By the Edo period, as Hokkaidō was colonized and shipment routes were organized, the use of kombu became widespread throughout Japan. Traditional Okinawan cuisine relies heavily on kombu as a part of the diet; this practice began in the Edo period. In Okinawa, the consumption of kombu per household is the highest of all prefectures. In the 20th century, a way to cultivate kombu was discovered and kombu became cheap and readily available everywhere.
Kombu is used extensively in Japanese cuisines as one of the three main ingredients needed to make dashi, a soup stock. Kombu is usually sold dried or in a dried shred called "Oboro kombu". It may also be eaten fresh as sashimi . Making kombu dashi is simple though kombu dashi powder may also be used. A strip of dried kombu is often boiled from the very first step of making a dish and is commonly eaten after cooking.
It is also important in Chinese cuisine and Korean cuisine.
Kombu may be pickled with sweet and sour flavoring and are cut into small strips 5 or 6 centimeters long and 2 centimeters wide. These are often eaten as a snack with green tea.
Kombu is a rich source of glutamic acid, an amino acid responsible for umami, one of the five basic tastes. Glutamic acid is used in the production of MSG.
It is often included when cooking beans, putatively to add nutrients and improve their digestibility.
(Japanese name followed by species)
- karafuto kombu L. saccharina contains mannitol and considered sweeter
- ma-kombu L. Japonica
- mitsuishi-kombu or dashi-kombu L. angustata commonly used in the making of dashi
- naga-kombu L. longissima
- Rishiri-kombu L. ochotensis commonly used for soup stock