Is miso soup vegan or vegetarian in Japan?

The short answer

Miso soup looks like the safest thing on the table, but in Japan it is usually neither vegan nor vegetarian. The reason is the broth: nearly all everyday miso soup is built on dashi made from katsuobushi (bonito) and sometimes niboshi (sardines). The soybean miso paste, the tofu, the wakame seaweed and the spring onion are all plant-based — it is the fish stock underneath that crosses the line. See is dashi vegan? for the full picture.

The hidden traps

Even "instant" miso has fish in it: convenience-store sachets and "dashi-iri" (dashi-blended) miso paste contain bonito or sardine extract. A topping of katsuobushi flakes can also land on the tofu. None of this is visible in the finished bowl, which is exactly why it surprises visitors.

How to get a plant-based bowl

The good news: a properly vegan miso soup is easy to make and increasingly easy to order. Shops that follow shojin ryori (Buddhist temple cooking) and dedicated vegan kitchens use kombu (kelp) or shiitake dashi, so the soup is 100% plant-based. Macrobiotic and organic cafes almost always do too. If you keep vegetarian rather than strict vegan, the same kelp-dashi bowls work for you.

What to say

Ask: "Kombu dashi no miso shiru wa arimasu ka?" — is there a kelp-stock miso soup? Recipes vary by kitchen, so when it matters, confirm with the staff before ordering; a quick question is always welcome.