Clam Miso Soup | Just One

Clam Soup (Clam Miso Soup)

Course: Soup
Cuisine: Japanese
Keyword: asari miso soup, clam soup, miso soup
Prep Time: 5 minutes
Cook Time: 5 minutes
Total Time: 10 minutes
Servings: 2
Author: Nami
Flavorful manila clam soup in dashi kombu stock, garnished with green onion. The umami from kombu matches perfectly with the delicious essence coming from clam stock.


  • ½ lb Manila clams (½ lb = 200 g)
  • 2 cups water (2 cups = 500 ml)
  • 2 inch kombu (dried kelp) (2" = 5 cm) (optional, see Notes)
  • 2 Tbsp miso (I use awase miso)
  • 1 green onion/scallion

For Degrit Clams:

  • 2 cups water
  • 1 Tbsp kosher/sea salt (use half for table salt)


  1. Gather all the ingredients.

    Japanese Clam Soup with Clear Broth Ingredients
  2. De-grit clams (Read my How To page for details and complete process). Even though they are “ready to use”, I highly recommend doing this process. Here’s a quick version. Add 1 Tbsp. salt in 2 cups water. Place a sieve in the bowl so that any sand and grit the clam purge would stay on the bottom of the bowl instead of being consumed by the clams again.
    Clam Miso Soup 1
  3. Place the clams inside the sieve without overlapping each other. The water level should be right around the clam’s mouth. If there isn’t enough salt water, make more using the same ratio of water and salt. Cover with aluminum foil (to make it dark) and leave it in a cool place for 2 hours. This should give clams enough time to purge sand and grit.
    Clam Miso Soup 2
  4. Wash the clams carefully with a brush. Clams are now ready to use.
    Clam Miso Soup 3
  5. Gently clean the dashi kombu with a damp cloth (DO NOT WASH) but leave the white powdery substances which contribute to the umami flavor in the stock.
    Clam Miso Soup 4
  6. Put clams, water, and dashi kombu in a pot and bring it to a boil over high heat.
    Clam Miso Soup 5
  7. When boiling, reduce heat to low.
    Clam Miso Soup 6
  8. Skim off scum and here’s how I do it. Prepare a cup/bowl of water and a fine mesh strainer and scoop off scum. Dip the strainer in water to clean while scooping.
    Clam Miso Soup 7
  9. Turn off the heat immediately after clams are all open. Remove the dashi kombu.
    Clam Miso Soup 8
  10. Add miso 1 Tbsp. at a time. Each brand of miso has different saltiness so adjust accordingly.
    Clam Miso Soup 9
  11. If you do not have a miso strainer, use a ladle and dissolve miso in there so you can make sure all the miso paste are dissolve before adding more.
    Clam Miso Soup 10
  12. When you are ready to serve, heat up miso soup, but DO NOT BOIL miso soup (because it will lose the miso flavor). Serve in miso soup bowl and sprinkle chopped green onion.

Recipe Notes

Kombu (dried kelp): If you don't have dashi kombu, you can omit; however the flavor will lack nice umami from kombu.

Preparation time is not including the time for de-gritting clams.

Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe in your own words and link to this post as the original source. Thank you.