What Is Kombu?

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For centuries, kombu has been a staple ingredient in Japanese cuisine, imparting broths, stews and seasonings with deep umami flavor. But what is it, how is it made, and how does its contributions to plant-based cooking support the environment?

Kombu is a type of kelp farmed and harvested primarily off the coasts of Hokkaido, Japan. The region’s cold, nutrient-rich waters make an ideal growth environment.

TYPES OF KOMBU

Kombu comes in several dried varieties. These are the most common:

Ma-Kombu – Considered the most popular type of kombu, this thick and leathery variety has a subtle sweetness and is often used to make dashi (Japanese soup stock).
Rishiri Kombu – Known for its thin but sturdy texture, this kombu yields a strong and aromatic flavor. It’s popular in dishes such as yudofu.
Hidaka Kombu – Softer in texture and with a slightly sweeter, milder taste, this kombu variety is ideal for oden broths and kombumaki. It’s also perfect for simmered dishes like tsukudani.
Rausu Kombu – Arguably the most flavor-saturated kombu, rausu kombu is ideal for those who prefer more robust broths or sauces. It’s also the favored kombu for kobujime, a curing technique wherein fresh fish is wrapped between layers of kombu.

Each type of kombu has its place in Japanese cuisine, but all share one defining trait: They enrich dishes with umami, the fifth taste.

HISTORY OF KOMBU

In the early 20th century, Japanese chemist Kikunae Ikeda identified the glutamic acid found in kombu as the key to umami, the savory flavor distinct from sweet, sour, salty and bitter. The discovery of this naturally occurring amino acid led to Ikeda’s later development of Monosodium Glutamate (MSG), a flavor enhancer that revolutionized food science (and, for a time, was an ingredient universally feared by Americans).

JAPANESE DISHES MADE WITH KOMBU

Today, kombu is responsible for the deep, satisfying flavors found in dashi, miso soup, and countless other Japanese dishes and seasonings. Among the most common are:

Dashi – This simple yet foundational broth is made by steeping kombu in hot water with bonito flakes.
Kombu Tsukudani – This simmered side dish comprises kombu seasoned in soy sauce, mirin, and sugar. To make it, Japanese cooks often use the steeped kombu that’s left over after making broth, as it’s been softened and is, therefore, easier to eat.
Konbucha – Not to be confused with the fermented kombucha tea sold in health food stores across America (which is a carbonated fermented beverage made from a tea and sugar base), this seaweed-based drink is made by steeping dried kombu by itself. Since it is neither fermented nor paired with other ingredients, its flavor is fresh and briny.
Furikake – This seasoning mix, wherein shredded kombu is combined with sesame seeds, dried fish, and other spices – is typically used as a garnish for rice.
Nimame – In this simmered soybean dish, kombu imparts umami flavor, and its enzymes help soften the soybeans, making them tender and easier to digest.

Recipe: Home-Brewed Kombucha Recipe

KOMBU IS SEAWEED, BUT SEAWEED ISN’T ALWAYS KOMBU

Like kombu, wakame and nori are dried seaweeds. However, they have their own distinct flavors, textures and applications.

Wakame is tender and mildly sweet, making it perfect for garnishing soups and salads.
Nori is thin, crispy and salty-sweet, which is why it’s used in sushi.

HOW IS KOMBU HARVESTED?

The majority of kombu is cultivated off the coast of Hokkaido, in northernmost Japan, where traditional seaweed farming methods have been refined over generations.

To grow kombu, spores are attached to ropes or bamboo rafts and submerged in the ocean. There, they grow into long, thick fronds until they’re ready to be pruned. Kombu cultivators then cut off only sections of the seaweed so that the oceanic plant can continue growing from its original holdfast (the main structural base of the seaweed).

After harvesting the kombu, it undergoes a maturation process called kuragakoi, during which it is stored in a controlled environment in order to develop its flavor and texture as it cures. The longer the kelp is cured, the more exquisite the flavor — and the higher the price.

3 ENVIRONMENTAL BENEFITS OF KOMBU

In recent years, kombu cultivation farms have become a key player in plant-based cooking programs and one of the most sustainable forms of aquaculture. That’s due to three key aspects of their harvest.

Unlike land-based crops, kombu doesn’t require fertilizer, pesticides or a freshwater source.
Kombu consumes carbon dioxide from the ocean, which creates a carbon sink that helps offset carbon emissions.
Kombu helps to maintain marine biodiversity and healthy ecosystems, with fish and shellfish using it as habitat.

Taken together, these benefits make kombu farming a low-impact agricultural method, a fact that anyone practicing ethical consumption and seeking plant-based protein alternatives can appreciate.

Olivia Carter

Olivia Carter is a seasoned chef with more than a decade of experience in restaurant kitchens in the Los Angeles area. A 2022 graduate of the Ģ��Ƶ, Olivia specializes in East and Southeast Asian cuisines and developing menus that accommodate dietary restrictions related to disabilities including SPD, OCD, ARFID, Autism and more. Currently, she is the head chef at a sorority kitchen in Indianapolis, providing exceptional meals to the next generation of women. When not in the kitchen, she works as a freelance culinary content writer, a skill she honed — in addition to food styling, R&D, set design and food photography — under the mentorship of Kiano Moju at Jikoni Studios.