Kombu seaweed is found in many countries around the globe, including Japan, Russia, China, Tasmania, Australia, South Africa, the Scandinavian Peninsula and Canada. In Japan, most kombu is harvested in Hokkaido, accounting for around 90% of total production.
Glacial Arctic Ocean waters that drift from Siberia to Hokkaido are rich in minerals and provide an environment that produces delicious kombu. Equipment used in Japan to dry kombu seaweed in the sun meets the most exacting sanitary standards, making Japanese kombu particularly popular worldwide.
Kombu seaweed from Hokkaido has long been distributed throughout Japan, and represents a major commercial challenge. Kombu seaweed harvested in Hokkaido used to be transported by boat, moving west along Sea of Japan coast to Osaka, a commercial center since that time.
For this reason, kombu seaweed wholesalers and processors are mainly located in or around Osaka. Kombu routes takes from Hokkaido to its destination is called the Kombu Route.
It extends as far as China via Okinawa. Ma-kombu, high-quality kombu, with its large, thick leaves, this is the most popular kombu. It has a refined sweetness and produces clear broths.
Ma-kombu leaves are light brown, 1 to 8 meters long and 13 to 30 cm wide. Lower parts are broad and narrowed near the stem.
Please note:
Very often, a whitish powdery substance may form on the surface of kombu or wakame seaweed. This is not mould but ‘mannitol’ contained in the seaweed. Mannitol is a type of sugar alcohol naturally present in seaweed, and it is the true identity of the white powder that appears on the surface of kelp.
Mannitol seeps to the surface with moisture during the seaweed drying process, and when the moisture evaporates, it adheres in the form of a white powdery substance. This white powder gives dashi a lot of flavour!
