Food & Drink

Hokkaido's unique konbu dials up the umami to 12

by Melissa Devaughn

Contributing Writer

Fisherman Kazuaki Ida entered the No Borders Cafe in Rausu just as we were finishing cups of hot coffee on a rainy Hokkaido afternoon. He held giant flat-leaved stalks that scraped against each other like hard plastic, garnering appreciative “ahs” of recognition among the cafe’s customers. As a first-time Hokkaido visitor and relative newcomer to authentic Japanese cuisine, I remained ignorant. What were these things and why was everyone so excited?

Turns out we were seeing the result of a lengthy process that converts this seaweed called konbu into a much-sought-after delicacy used to flavor soup stocks and enhance Japanese cuisine. Konbu is a mainstay of Japanese cooking, and not only were we in the epicenter of konbu production, but we also were meeting one of the masters of harvesting the seaweed.

Hokkaido produces some 90 percent of all konbu, and high-end restaurants the world over covet its quality. The cold waters and nutrients that flow through the Sea of Okhotsk are responsible for the konbu’s superior flavor.

Ida, 65, lean and weathered from decades among the elements, has been harvesting konbu with his family since he was a boy. As head of the konbu division of the Rausu Fisheries Cooperative Association, he is the local expert when it comes to this unassuming sea product that holds such importance in Japanese cuisine.

“Of course, Hokkaido’s konbu is the best in Japan,” Ida says. The reasons are many, he adds: the cold water, the rich land and the winter sea ice — all contribute to its superiority. “And Rausu konbu is the best of them all.”

Ida is certainly passionate about his product, but he is also part-scientist, he explained. The level of umami, a taste sensation intrinsic to Japanese cuisine, is how one numerically measures the quality of a dish, and soup stocks, or dashi, are the starting point. The very best restaurants and chefs seek the highest umami rating possible.

Most konbu, Ida said, has an umami level of 8. To create a truly excellent dashi, the umami must reach level 12. So, chefs add bonito to their stock. The fish contributes inosinic acid to the konbu, thus elevating the stock to the desired umami rating of 12.

“But the stock taken from Rausu konbu records level-12 umami without inosinic acid,” Ida says, meaning dashi can be made with Rausu konbu alone.

Naoko Goto, a naturalist and guide in Rausu, says visitors to the area are surprised to learn about konbu’s vital role in Japanese cuisine. She began offering tours during the konbu harvest so that visitors could better understand its relevance.

“We study the history of konbu and the culture surrounding it,” Goto says. She also tries to impress on visitors the key role that the fishery plays in supporting the commercial fishing economy in Rausu, a community of fewer than 6,000 people who depend on the sea for their livelihoods.

Ida, one of the select few permitted to harvest konbu, says the process has barely changed over the years. There is a short 30-day harvest window and a time-consuming 23-step process to collect, dry and market the konbu.

“It’s manually harvested by one fisherman aboard a small boat,” he says. The fisherman drags a long rod with a pronged tip along the sea floor to twist and then pluck each strand of seaweed by its roots.

Ida said the konbu is located using a depth finder, which relays data about the situation underwater to a device on deck. The weed grows at depths of between one and 10 meters.

“It is not difficult (to find),” he says, “but it’s hard work.”