To Make the Dashi (Can be Made in Advance):

• Clean any dirt off the kombu with a damp towel and soak the kombu in water for 30 minutes or overnight (preferred). NEVER wash kombu and do not remove the white substance—that’s umami! These days, it's pretty clean, so you can usually skip this cleaning step. Just make sure there are no dirt particles.
  
• After 30 minutes (or overnight), the kombu is rehydrated. This liquid is called cold brew Kombu Dashi.
  
• Pour the kombu dashi and kombu into a saucepan. SLOWLY bring it to boil on medium-low heat so you can extract as much umami from kombu as possible. Right before the stock boils, remove the kombu. If you leave the kombu, it gets slimy and yields a bitter taste. Now, what you have is Kombu Dashi. If you’re vegetarian/vegan, use this kombu dashi for your miso soup. What to do with the used kombu? You can reuse it to make Simmered Kombu or Homemade Furikake Rice Seasoning.
  
• If you're not vegetarian/vegan, add the katsuobushi to the kombu dashi and let it simmer for 30-60 seconds. Turn off the heat and let it steep for 10 minutes.
  
• Strain through a fine-mesh sieve and now you have roughly 4 cups of Awase Dashi. You can store the dashi in the refrigerator for up to 3-5 days and in the freezer for up to 2 weeks. Repurpose the used katsuobushi to make Homemade Furikake Rice Seasoning.
  

To Make the Miso Soup

STEP 1 - Add the Dashi

• Here, I demonstrate how to make 2 servings of miso soup. Add 2 cups (480 ml) dashi to a saucepan and set over medium heat. You can use the formula of 1 cup (200-240 ml) dashi + 1 Tbsp (18 g) miso = 1 serving of miso soup. If you add more ingredients/vegetables, the amount of soup will increase, and you will also need more miso.
  
• Are you in a hurry and have no time to make dashi? You can use a dashi packet or dashi powder from the store to make instant dashi.
  

STEP 2 - Add the Dense Ingredients (BEFORE bringing the dashi to a boil)

• If your miso soup doesn't include hard ingredients or clams, go to the next step. Add the hard ingredients like root vegetables to the saucepan. Once boiling, lower the heat and simmer until they become tender. If you're making Clam Miso Soup, add the clams to the cold brew kombu dashi, then bring it to a gentle boil. Once the shells are open, turn off the heat (do not overcook).  
  

STEP 3- Add the Quick-Cooking Ingredients (AFTER the dashi is boiling)

• If your miso soup doesn’t include these ingredients, bring the dashi to a boil and go to the next step. After the dashi starts boiling, add in the soft vegetables like leafy greens, mushrooms, and deep-fried tofu pouches because they require less cooking time. At this point, keep the soup at a simmer and make sure it stays warm (DO NOT OVERBOIL).
  

STEP 4 - Add the Miso

• Add a small amount of miso at a time (you can start with 2 Tbsp miso for 2 cups dashi). Put the miso inside a ladle, slowly add the dashi into the ladle, and stir with chopsticks to dissolve the miso completely. You can buy a miso muddler or a fine-mesh miso strainer, which helps you dissolve the miso faster. If you accidentally add too much miso, dilute the miso soup with dashi (or water). NEVER OVERBOIL miso soup because it loses nutrients, flavor, and aroma.
  

STEP 5 - Add the Tofu

• Add the tofu after the miso is completely dissolved; otherwise, you might break the tofu when stirring in the miso. If you add chilled tofu from the refrigerator, the miso soup will get cooler. Reheat the miso soup until it is just hot, but NOT BOILING.
  

STEP 6 - Add the Wakame and Green Onions

• Add the rehydrated wakame (seaweed). I recommend rehydrating dried wakame in a separate bowl of water to get rid of the saltiness, instead of rehydrating it in the soup itself. Add the ingredients that do not require cooking such as the chopped green onions, mitsuba, yuzu, and blanched spinach right before serving to keep their fresh fragrance and color.
  

To Serve:

• Serve immediately. Place on the right side of the table setting (read about this on Ichiju Sansai (One Soup Three Dishes); see the diagram).
  

To Store:

• In general, it's best to consume all the miso soup right away because the aroma and taste will be lost as time passes. Let your miso soup cool to room temperature (up to 4 hours; any longer and it will spoil) and then refrigerate. Keep for up to 2 days in the refrigerator. If you want to make a big batch to store for later, it's best to refrigerate the soup without adding the miso. When ready to use, add the miso only for the portion you need. You can freeze miso soup for up to 2 weeks. If the soup contains potatoes or tofu, remove them before freezing as the textures will change.

To Reheat Miso Soup:

• Heat the miso soup in a pot over medium heat, but do not overboil. Miso loses its nutrients at high temperatures.