Glossary - Kitchen Tools

Soup Strainer


In Japan, this cooking utensil is used to make delicious "dashi" (Japanese broth), a basic of Japanese cuisine

What is soup strainer?

Soup strainer (dashi koshi-ki, だしこし器 in Japanese) is a cooking utensil used to remove dashi ingredients and extract only the broth. In Japanese cuisine, it is primarily used when making "dashi" (Japanese broth) from niboshi (dried sardines) or katsuobushi (bonito flakes). It is a metal strainer with a very fine mesh inside a handled metal frame, allowing even fine bonito powder to be filtered out. It is used in dishes that require dashi, such as clear soups, simmered dishes, and chawanmushi (steamed egg custard).

How to use

Set the dashi soup strainer over a heat-resistant bowl and slowly pour the dashi through it.


Substitute for soup strainer: when you don’t have it 

You can achieve the same filtering effect by spreading a paper towel or cloth over a strainer and pouring the dashi through it. Additionally, a "chinois," a fine-mesh strainer used in French and Italian cuisine, can also be used as a substitute.



The dashi ingredients left in the soup strainer can be reused instead of being discarded. For katsuobushi (bonito flakes), you can fry them in a pan, add soy sauce, mirin, and sake, and cook until the moisture evaporates to make a furikake (rice seasoning). For kombu (kelp), chop it finely and simmer with soy sauce, mirin, and sake until the liquid is gone to make tsukudani (a type of preserved food).


Do not squeeze the ingredients left in the strainer to extract more dashi, as this can release bitterness and cloud the broth, making it less tasty.

Cooking Basics

Dashi - how to make from kombu and dried bonito flakes

Ingredients (for 800 ml / 27 fl. oz. of dashi)

10 g (3 × 25 cm / 1.2 x 10 in.)
Katsuobushi/bonito flakes
20 g (0.7 oz.)
1000 ml (33.8 fl. oz.)


Soak the kombu in water for 30 minutes, then heat over medium heat. Just before the water comes to a boil, remove the kombu and turn off the heat. After a few minutes, add in the bonito flakes and allow to sit for 2 minutes.  Place a dampened paper towel over an all-purpose strainer and strain the dashi.

Dashi - how to make from sardines

Ingredients (for 800 ml / 27 fl. oz. of dashi)

Dried sardines
30 - 40 g (1 - 1.4 oz.)
100 ml (33.8 fl. oz.)


Remove heads from the dried sardines and split the bodies into two halves to remove the innards. Place the dried sardines into water and allow to soak overnight, or for at least 30 minutes if you need to save time, then heat over medium heat. When scum begins to form on the surface, simmer for about 5 minutes while skimming off the scum. Place a dampened paper towel over an all-purpose strainer and strain the dashi.

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