Japanese Kelp Kombu

Japanese Kelp Kombu 昆布

Umami | Kombu in Japanese Cooking | Hokkaido Kombu | Buy Kombu

Dried kombu

Japan being an island country, it may come as no surprise that Japanese cuisine relies heavily on products taken from the sea. Not only fish, shrimps, crabs and other oceanic creatures but also a large variety of seaweed.

Wakame and nori may be the most widely known of these seaweeds outside of Japan. Nori as an essential part of maki sushi (sushi rolls), wakame for the delicious wakame soup accompanying many traditional Japanese dishes.

Then, there is kombu, Japanese edible kelp. Kombu, growing in the cold waters around Hokkaido and parts of Tohoku, made a comparatively late entry into Japanese cuisine.

Sure, kombu was delivered to the court of the Shogun as a tribute by the rulers of the northern domains already in Edo times (1603-1868) but kombu really took off in the general Japanese kitchen during the Meiji period (1868-1912) when Japan fully colonized Hokkaido.

Steam ship ferries and the newly constructed railway system made kombu, previously mainly a staple in Ainu cooking, available all over the country at a low price.

Amazingly, the southern-most island group of Okinawa, only recently acquired after a war with China (1894-95) picked up on the kombu the strongest. Okinawans know what's tasty and are generally more than ready to incorporate new ingredients into their cooking.

Fishing for kombu in Rausu, Hokkaido

Umami

Meanwhile, in mainland Japan, Tokyo Imperial University chemistry professor Kikunae Ikeda (1864-1936) sensed during a meal that featured a soup made of kombu dashi (kombu soup stock) a taste he had never encountered before. It was not in the usual range of sweet, sour, bitter and salty. Ikeda immediately focused his studies on that so far unclassified taste. In 1908, he was able to identify Glutamic acid as the source of this particular taste. Kombu is particularly rich in Glutamic acid.

Ikeda named his newly discovered taste variety umami, drawing from the word umai (delicious) in Japanese. Today, umami is a taste variety recognized world-wide.

Rishiri Kombu at Wakkanai Fish Market, Hokkaido

Kombu in Japanese Cooking

Japanese cooks and housewives most likely missed the newspaper stories reporting Ikeda's discovery. They were the ones to actually put that northern sea weed to real use.

Kombu leaves were large and they usually came air dried, the only way to keep them edible after their long journey from Hokkaido.

Cut up into small pieces and boiled, kombu leaves would make for a perfect dashi soup stock, they soon discovered.

Soups based on kombu by itself, soups using kombu in combination with shaved bonito flakes (katsuobushi), kombu combined with shiitake mushrooms, with dried sardines or tobiuo (flying fish), kombu with any type of vegetable. The combinations are endless.

Soon, kombu dashi became the most popular Japanese soup stock, employed in the making of miso soup (a soup that goes with most traditional Japanese meals) as well as in many other types of soup.

Boiled kombu on the other hand could be a great addition to sashimi fish platters.

Small pieces of kombu were frequently added when preparing sushi rice. The strong umami qualities of kombu bringing out the taste of the rice all the stronger and with it, the taste of the sushi.

Boiled and further processed kombu is also frequently employed as tsukudani (rice toppings), and boiled kombu is often served in Japanese salads.

Thick layers of boiled kombu are also rolled up around minced herring. That particular dish, known as kobumaki has become one of the staples of osechi ryori (New Year's Day dishes) but is also enjoyed in other seasons as part of traditional Japanese meals.

It's usually called kobumaki (and not kombumaki) because kombumaki would be somewhat cumbersome to pronounce. The kobu part of the word is taken from yorokobu, meaning being happy or glad.

Rishiri Island

Hokkaido Kombu

Kombu grows as a dense forest on the ocean floor, often in coastal waters.

In the northern regions of Hokkaido, most famously in the waters near Rishiri Island, a small island off the far northwest of Hokkaido, as well as the sea off the Shiretoko Peninsula in the far northeast of Hokkaido, fishermen harvest naturally grown kombu from their boats.

This type of kombu is marketed as tennen (天然), as a product taken straight from the wilds of nature.

Rishiri Kombu and Rausu Kombu are the most famous varieties of tennen kombu sold in Japan today. Rausu being a very picturesque village on the eastern side of the Shiretoko Peninsula, home to many kombu fishermen braving the cold ocean here.

In the south of Hokkaido, kombu tends to be farmed. That is, the kombu forests grow under direct supervision of the fishermen and are regularly harvested.

The two most famous brands from southern Hokkaido are Hidaka Kombu from the town of Hidaka and Shiroguchihama Kombu produced in an area known as Minami Kayabe.

When cutting Shiroguchihama Kombu, the inside of the leaves turns out to be white. Pure mannitol showing up, the sugar alcohol built up inside the salty plant. It's exactly that mannitol that is responsible for the strong umami taste of kombu.

Minami Kayabe, located near the city of Hakodate in the very south of Hokkaido was a Japanese domain already in Edo times. The local ruler not only paid his tribute to the Shogun in Edo with the locally grown kombu but also delivered it all the way down to the Imperial Court in Kyoto.

Rishiri Kombu

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Kombu as such is generally sold in dried form. When you open a package of dried kombu, some of the dried leaves will have a white residue on them. That is not mold, it is the mannitol making its way to the surface. The very substance responsible for the taste of the kombu.

Dried kombu can be shipped internationally. Kobumaki are best enjoyed on your visit to Japan.

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