In Japanese cuisine, there’s a secret ingredient that often forms the foundation of countless flavorful dishes: dashi broth.

This broth delivers a signature umami taste and serves as the base for soups and a wide variety of broth-based dishes. One particularly popular type of dashi—especially among vegetarians—is kombu dashi.

This article will thoroughly explore how to make kombu dashi and the many delicious dishes that can be prepared using this simple yet flavorful stock.

What is Kombu Dashi?

Dashi is a traditional Japanese broth that underpins many types of soup and other liquid-based dishes. Unlike meat-based broths such as chicken or beef stock, kombu dashi is made from a type of edible kelp called kombu.

Kombu is a dark, dried seaweed rich in natural glutamate—the compound responsible for the fifth taste known as umami.

When kombu is soaked in water, the glutamate is released, resulting in a light but deeply flavorful broth.

Kombu dashi is one of the simplest forms of dashi and can be made using just water and kombu. However, it’s not uncommon to enhance the flavor with katsuobushi (dried bonito flakes), which adds a smoky, savory depth.

How to Make Kombu Dashi

To achieve a clean and balanced flavor, one of the best methods is to soak kombu in water for several hours or overnight.

Here are the steps:

• Take about 10 to 20 grams of dried kombu (no need to rinse it)
• Cut the kombu into smaller pieces for better extraction
• Place the kombu into a container with about 1 liter of clean water
• Cover the container
• Let it sit for at least 6 hours, or preferably overnight
• After soaking, gently heat the dashi over low heat
• Remove the kombu from the water just before it reaches a boil
• If desired, heat the broth again and add katsuobushi for extra flavor
• The kombu dashi is now ready to serve or use in cooking

This method of making kombu dashi results in a clear, light, and smooth broth that carries the subtle yet rich umami of seaweed.

Dishes That Use Kombu Dashi

Thanks to its mild yet delicious flavor, kombu dashi is a key ingredient in a variety of Japanese dishes. The most famous example is miso soup, which often uses kombu dashi as its base—especially in vegetarian versions.

Kombu dashi is also used in preparing nabemono (Japanese hot pot dishes), such as yudofu (Kyoto-style simmered tofu) or vegetarian shabu-shabu.

Another well-loved dish that benefits from the deep flavor of kombu dashi is chawanmushi, a savory egg custard that is soft, silky, and full of umami.

Even some modern vegetarian ramen recipes use kombu dashi as a substitute for traditional meat-based stocks, offering a lighter alternative that still delivers a satisfying taste.

How to make kombu dashi is straightforward, making it easy to incorporate into everyday home cooking. Simple dishes like sautéed vegetables or dipping sauces for cold soba noodles can be significantly enhanced by adding just a bit of this versatile broth.

With its wide range of uses and impressive flavor profile, it’s no wonder that how to make kombu dashi continues to be a popular topic among Japanese food lovers and those embracing a plant-based lifestyle.

Image: Plant-Based Matters