How do I prepare a dashi stock from scratch, and what is the role of kombu and bonito flakes?

Question

How do I prepare a dashi stock from scratch? Learn the simple but essential roles of kombu (kelp) and bonito flakes for this umami base.

Answer 1

To prepare dashi, simmer kombu in water, then remove it before bringing the liquid to a boil. Add bonito flakes, simmer briefly, then strain. Kombu provides umami and depth, while bonito flakes add a smoky, savory flavor.

Detailed Explanation:

Dashi is a fundamental Japanese stock that forms the base for many dishes like miso soup, noodle broths, and simmered dishes. Here's how to make it from scratch:

1. Prepare the Kombu: Take a piece of kombu (dried kelp), about 4-5 inches long. Wipe it clean with a damp cloth to remove any surface salt or residue. Do not wash it vigorously, as you want to retain its natural flavor.

2. Infuse the Water: Place the kombu in a pot with 4 cups of cold water. Let it soak for at least 30 minutes, or up to a few hours. This allows the kombu to slowly release its umami-rich compounds into the water.

3. Simmer (Do Not Boil): Gently heat the pot over medium heat. Just before the water starts to boil (small bubbles will form around the edges of the kombu), remove the kombu. Boiling the kombu can make the dashi bitter.

4. Add Bonito Flakes: Bring the kombu-infused water to a boil. Add a handful (about 1 cup) of bonito flakes (katsuobushi) to the boiling water.

5. Simmer Briefly: Let the bonito flakes simmer for about 30 seconds to 1 minute. Do not stir. The flakes will sink to the bottom.

6. Strain the Dashi: Turn off the heat and let the bonito flakes settle. Strain the dashi through a fine-mesh sieve lined with cheesecloth or a paper towel. This removes the bonito flakes, leaving you with a clear, flavorful broth.

7. Use Immediately or Store: Use the dashi immediately in your recipe, or store it in an airtight container in the refrigerator for up to 3 days.

The kombu provides glutamates, which contribute to the umami, or savory, flavor of the dashi. It gives the stock a subtle sweetness and depth. The bonito flakes, made from dried, fermented, and smoked skipjack tuna, add inosinates, another umami compound, as well as a distinct smoky and slightly fishy flavor that complements the kombu perfectly. Together, they create a balanced and complex flavor profile.

Pro Tip:

Don't discard the kombu and bonito flakes after making dashi! You can reuse the kombu by slicing it thinly and simmering it with soy sauce and mirin for a flavorful side dish called 'kombu tsukudani.' The used bonito flakes can be added to rice porridge or used as a topping for okonomiyaki.