🍲 Dashi Yield Calculator (Ingredient by Water Volume)

Dashi (出汁) is the umami-rich stock that underlies Japanese cooking - miso soup, simmered dishes, noodle broths and sauces. It is made from a small set of ingredients whose ratios are tradition, not guesswork:

Because the solids trap liquid and some evaporates, the yield is about 90% of the water volume - 1 litre of water makes roughly 900 ml of finished dashi. Kombu dashi can be made cold overnight (water extraction) or gently heated, while katsuobushi and niboshi need a brief simmer and straining.

The calculator scales the classic ratios linearly with water volume. For example, 1.5 litres of water needs 15 g of kombu for kombu dashi, or 45 g of katsuobushi for katsuobushi dashi. Yield is estimated at 90% of water volume after straining.

Awase dashi (kombu + katsuobushi) is the most common stock for miso soup and noodle broth - you get the kombu’s glutamates plus the katsuobushi’s inosinate, a textbook umami synergy.

1. Choose the dashi style you want to make.
2. Enter the amount of water (default 1 L).
3. Read the exact ingredient amount needed.
4. Check the estimated finished yield (about 90% of water volume).
5. Follow the method table for timing and straining.

How much kombu do I need for 1 litre of water?

10 g of kombu per 1 L is the standard ratio. Scale linearly: 15 g for 1.5 L, 20 g for 2 L.

What is awase dashi?

A stock made from both kombu and katsuobushi - typically 10 g kombu + 30 g katsuobushi per litre. It is the classic base for miso soup and udon broth.

Can I reuse the ingredients?

Yes. The strained kombu and katsuobushi can be simmered again for a lighter second stock (二番だし), or chopped and seasoned as a topping.

How long does dashi keep?

In the fridge, 2-3 days. It freezes well - pour into ice-cube trays and pop out single portions for soups and sauces.

Is kombu dashi vegan?

Yes. Kombu (kelp) and dried shiitake stocks are fully plant-based. Katsuobushi (bonito) and niboshi (sardines) are fish-based.

Why is my yield less than the water I started with?

The solids retain some liquid and evaporation removes the rest. Expect about 90% yield: 1 L in, ~900 ml out.

Do not boil kombu - it turns bitter and slimy. Remove it just as the water begins to bubble. Use the leftover katsuobushi and kombu for a second, weaker stock (二番だし) or as furikake. Store dashi in the fridge for up to 3 days or freeze in ice-cube trays. If you need a vegan stock, kombu and shiitake are both plant-based; katsuobushi and niboshi are fish. For measuring, 30 g of katsuobushi is about two generous handfuls, and one piece of dried shiitake weighs roughly 5 g. Pair your stock with our Washoku recipe scaler to scale seasoning (soy sauce, mirin, miso) for the amount you make, and check the rice calculator for the bowl it goes with.