Umami rich ingredients
Kombu (kelp)

What is Kombu?

Kombu is the most important ingredient used to prepare Japanese soup stock 'dashi'

Kombu belongs to the brown-algae family harvested on the coasts of Hokkaido, the northern island of the archipelago and in Tohoku, the north-eastern part of the main island of Honshu. There are various species of algae. Among them, those most commonly used for dashi (Japanese stock) are ma-kombu, rishiri-kombu, and rausu-kombu. Hidaka-kombu is simmered with seasonings and is eaten as a side dish such as simmered kombu or takiawase. Kombu that is used in the preparation of dashi is grown for two years and harvested from July through September.

Major Kombu varieties

  • Ma-kombu

    Also known as yamadashi kombu, this variety has light brown, wedge-shaped fronds.

  • Rausu-kombu

    The wide, thin fronds of rausu-kombu ensure that its flavor is easily drawn out when making dashi.

  • Rishiri-kombu

    Harvested from islands at the very top of Japan, rishiri-kombu is often considered the best kombu for dashi.

  • Hidaka-kombu

    This variety is characterized by its dark color and its softness and is also used for cooking.

How Kombu is made

As with dashi made from other ingredients, the time taken to make kombu dashi is short while the process of making dried kombu is rigorous and time-consuming. Kombu thrives in the cold waters off Hokkaido in the north of Japan, tending to inhabit waters around five to eight meters deep and generally takes around two years to reach the level of maturity required for harvesting. Harvesting usually only takes place during the summer months of July to September, on dates determined annually, and is traditionally carried out by kombu harvesters in boats. Long wooden poles with hooks attached are used to detach the kombu from the seabed at the root.

As soon as the kombu reaches land, it is laid out on rocks to dry. On a summer day, this process can be completed in four or five hours. Once dry, the kombu is taken indoors, the shape of each frond is adjusted, and then it is dispatched. Alternatively, some kombu undergoes a further maturation process known as kuragakoi (cellar conservation). This process improves the flavor of the kombu and removes its distinctive seaweed odor.

Kombu and glutamate

Dried kombu is abundant in the umami substance glutamate.

Levels of naturally occurring glutamate Levels of naturally occurring glutamate Levels of naturally occurring glutamate

Kombu and Dashi

The choicest kombu used to be shipped with great care from distant Hokkaido to Kyoto, the ancient capital of Japan that flourished for nearly a thousand years. In the Heian period (794–1185), shojin ryori, a type of vegetarian cooking, was introduced along with the teachings of Buddhism that warned against the taking of life. The ingredients used in shojin ryori consist entirely of vegetables and soybean products–meat, fish, or seafood are never used. Kombu dashi is indispensable for the enhancement of the taste of the vegetables used in shojin ryori. The dashi used in Japanese cuisine is very easy to make. Have you ever tasted a kombu dashi in its purest form? If you have not, cut a piece of kombu, put it in a cup, and add water. Let it sit for about 20 minutes. Dashi will begin oozing out from the kombu in a few minutes. Try it. A light, subtle taste will fill your mouth. What makes the dashi so indescribably delicious is the umami. The main umami substance in kombu dashi is glutamate and aspartate.

Dashi most commonly utilizes a combination of kombu (kelp seaweed) and katsuobushi (dried bonito flakes), but other ingredients used to make dashi are shiitake mushrooms and niboshi (small dried fish). Dashi-making has evolved over a long period of time. Boiling is known to have been used in Japanese cooking since the Jomon period (c. 13,000–300BC), and the stock from shellfish and fish-bones was used to flavor other dishes.

What is Dashi? What is Dashi?

Japanese cuisine with delicious umami

By the seventh century a dashi using kombu and katsuobushi had developed. This was refined further and has become Japan’s most indispensable cooking stock, generally used in two forms – ichiban (primary) dashi and niban (secondary) dashi. Despite its hidden role, dashi could be said to be the heart of Japanese cuisine, not because of the prominence of its own flavor, but because of the way it enhances and harmonizes the flavors of other ingredients. The secret of Japanese cuisine is this art of enhancing and harmonizing.

What is Dashi?

A great variety of fresh food ingredients is available in Japan, with its regional diversity, clearly differentiated seasons and fertile soil. Washoku, Japanese cuisine, has a tradition of cherishing each season. With umami, chefs bring out the flavors of those seasonal ingredients. Keeping to tradition, they devote themselves to innovation. Please enjoy their umami dishes.

Umami in Washoku

What is Umami?

Umami is the fifth taste, joining sweet, sour, salty and bitter. These are unique tastes that cannot be created by mixing other tastes, and are known as the basic, or primary tastes. Umami is a general term used mainly for substances combining the amino acid glutamate, and/or the nucleotides inosinate and guanylate, with minerals such as sodium and potassium.

What is Dashi

Whether something tastes good or not is a comprehensive yet subjective evaluation determined by elements such as taste, aroma, texture and temperature, besides other factors such as appearance, color and shape, as well as one’s physical condition, surrounding environment, cultural background, and previous experiences. Of these various elements, umami in balance with the other basic tastes (sweet, sour, salty, and bitter) plays an important role in determining the deliciousness of a dish.

What is Dashi? What is Umami