Kombu, or edible kelp, has caught on in the United States, appealing to many top chefs who appreciate the deep umami flavors it can add to their dishes and offering vegetarians a welcome new addition to their diets.

In Japan, various kinds of seaweed have contributed to the country's culinary culture. Among them, some species of algae seaweed, such as nori -- used to wrap rice -- and "wakame" -- typically added to miso soup -- are already familiar to Americans thanks to the worldwide popularity of sushi.

Ebony Haywood, a pastry chef of a three-starred Michelin restaurant in Washington, holds up dishes of kombu at a tasting event in the capital held in late January 2023. (Kyodo)

Kombu is often used to make stocks but also has a range of other uses, all of which its promoters want to introduce to U.S. foodies.

A food-tasting event was held in late January at Sushi Taro, a top Japanese restaurant in the capital Washington. It featured premium kombu, melons, persimmons and strawberries from Japan.

Nearly 20 chefs, mostly from Michelin-starred restaurants in the area, tried dishes of simmered salmon kombu rolls, "udon" noodles with kombu broth, and other fare involving the ingredient, such as soy-marinated kombu with dried squid, carrot and herring roe.

There was also a corner to introduce "oboro" kombu (shredded kelp) and "shio" kombu -- kelp boiled in soy sauce, mirin and sugar that has been dried and cut into small pieces. Fascinated by the way the dishes were prepared, some participants took videos.

Ebony Haywood, a pastry chef of a three-starred Michelin restaurant in Washington, holds up a salted kelp dish at a tasting event in the capital held in late January 2023. (Kyodo)

Ebony Haywood, 46, a pastry chef at a Michelin three-starred restaurant, was introduced to kombu stock about six years ago in Washington and became an instant fan of the "depth of umami flavor" it provides.

"Kombu is becoming more and more popular. More Asian flavors have been introduced at restaurants here," Haywood said.

One chef said he encountered kombu in Latin America and another said he first tasted it in Japan. Both are now trying to create original dishes using it.

Kombu is believed to have started drawing worldwide attention around 15 years ago. Okui Kaiseido, a long-established kombu specialty store in Fukui Prefecture, central Japan, hosted a tasting event in 2006 when the history of kombu was introduced at a food and culture conference held in Paris.

Clear broth and an abundance of minerals are Okui's main selling points for its kombu, while the recent surge in vegetarians is also working in the company's favor.

The Japanese government, meanwhile, has started to support kombu exports to the United States.

Nobu Yamazaki, 52, the chef and co-owner of Sushi Taro who was one of the organizers of the January event, said his goal is for the American public not only to appreciate kombu as a broth but also enjoy the full experience of its various uses.

"Our tasting event was to increase recognition of kombu among leading chefs in the various ways people can eat and cook with it," Yamazaki said. "If delicious kelp becomes more readily available in the U.S., ordinary households will be able to enjoy it."

Takashi Sadakane, counselor at the Embassy of Japan in Washington who has a background in economic affairs, said Japanese companies must get to know the tastes of the American public to properly market kombu.

"In what form can kombu be popularized among American consumers? Promotion is required with a market-in, not a product-out approach," he said, noting that this is a challenge Japan faces for a range of food items as it seeks to achieve its goal of 5 trillion yen in food exports.

A participant of a kombu tasting event held in Washington takes a video of a dish being cooked in late January 2023. (Kyodo)

Kelp rolls containing salmon are served at a kombu tasting event in Washington held in late January 2023. (Kyodo)