Kombu or katsuobushi? What is in your Japanese dashi

A bowl of soup can look almost empty and still contain fish. In Japanese cooking, dashi is the stock behind many dishes, not a single ingredient with a fixed recipe. Knowing a few of its names helps you ask what is in a meal—and understand why two apparently similar broths taste different.

The useful starting question is not “Does this have dashi?” but “What is the dashi made from?” A vegetable topping tells you little about the liquid underneath it.

Four ingredients behind the word

Kombu (昆布) is kelp. The Umami Information Center explains that it can be used on its own for a vegetarian stock, as well as combined with other ingredients. Its presence does not establish that a finished dish contains only plant-derived ingredients: a kitchen may also use fish in the stock or elsewhere in the recipe.

Katsuobushi (かつお節) is processed skipjack, often described in English as dried bonito. It is fish, even when the flakes have been strained out. Japan’s agriculture ministry distinguishes production methods: arabushi is boiled and smoke-dried, while karebushi undergoes an additional mould-ripening stage. Not every kind of katsuobushi should therefore be described as mould-fermented.

Niboshi (煮干し) means small fish that have been boiled and dried. Producer Ninben explains that sardines are the usual reference, although other fish are also used. This is another fish-based route to dashi, not a vegetable alternative to bonito. The Umami Information Center describes niboshi stock as more noticeably fishy than katsuobushi stock and suitable for dishes such as miso soup.

Dried shiitake (干し椎茸) is another stock ingredient, including in vegetarian cooking. Its mushroom aroma gives a different starting point from kelp alone. Recognising the name is useful; assuming every mushroom dish uses only mushroom stock is not.

A further menu word worth spotting is ago (あご), flying fish. Ninben describes yakiago as flying fish that is grilled and then dried. A less familiar stock name is not necessarily a fish-free one.

First and second describe the extraction

You may encounter ichiban dashi (一番だし) and niban dashi (二番だし). In the kombu-and-katsuobushi method described by the Umami Information Center, ichiban is the first stock. Niban is a second extraction using the ingredients left from the first, cooked again with water.

That is a distinction in method, not a reason to dismiss a dish made with the second stock. The centre lists simmered dishes and miso soup among uses for niban dashi. For a diner, the relevant question is how the stock suits the dish, not whether its name sounds like a league position.

Ask about the whole dish

If you avoid fish, try a concrete question: “Does the stock contain katsuobushi, niboshi or any other fish ingredients?” In Japanese: 「だしに、かつお節や煮干しなどの魚の材料を使っていますか？」

Then explain what you need excluded from the whole dish, including sauces and toppings. A clear broth, a tofu main or a vegetable garnish is not an ingredient declaration. If an allergy is involved, tell the restaurant explicitly; this vocabulary guide cannot establish whether a particular kitchen can prepare a suitable meal.

For cooking at home, first decide whether you want a kelp-only, mushroom-based or fish-based stock. With a packaged product, read the full ingredient list rather than relying on the ingredient pictured on the front.

You do not need to memorise every regional style. Recognising a handful of names turns “Japanese stock” from an anonymous background flavour into something you can choose and ask about with confidence.

Ingredient and preparation guidance checked on 9 October 2026. This is a food-knowledge guide, not a restaurant review or a claim about any individual menu.