Dashi stock is the foundation of Japanese soup stock and is used in a variety of dishes in Japanese cuisine. It will make any dish taste better once you know how to use it in your daily cooking. Dashi plays a different role than other seasonings, such as salt, sugar and miso. Dashi is an umami-rich liquid made from kombu and bonito flakes. By combining it with other ingredients and seasonings, it gives a dish deep, satisfying flavor, and the umami effect reduces the amount of salt needed. By combining ingredients, dashi offers unlimited possibilities.
How to prepare kombu dashi stock (plant-based)
Kombu dashi is made by soaking pieces of kombu in water and then gently heating them in water over low heat until just before the water reaches the boiling point (150 degrees Fahrenheit/ 65 degrees Celsius). This stock has a slightly stronger umami flavor than cold brew kombu water, as the gentle heat helps release more flavor into the liquid. Use for miso soups and noodle broths, as well as dressings, sauces, stir-fries and simmered dishes. Kombu dashi has a savory flavor with a hint of the ocean.
- ¾ oz (20 g) kombu
- 4 cups (1000 ml) water
2. Heat the kombu (in the same saucepan with the soaking liquid) over medium-low heat just until you start to see small bubbles around the edge of the saucepan pot (150 degrees Fahrenheit/ 65 degrees Celsius). Make sure not to boil the water. Remove from the heat.
3. Remove the kombu from the saucepan. Store the dashi in a resealable plastic bag or a container with a lid in the refrigerator for up to 2 days, or in the freezer for up to one month. You can reuse the kombu by repeating the same process with 50% less water.
How to prepare basic dashi stock (first brew)
This is the most popular type of dashi stock, which is made with a combination of kombu and katsuobushi. Basic dashi stock has intense flavor with an elegant aroma that goes well with clear soups, delicate dishes such as steamed egg custard (Chawanmushi), and vinaigrettes (sunomono) to highlight deep savory umami flavors. The umami ingredients glutamic acid and katsuobushi as inosinic acid are combined here, and it is said that the synergistic effect increases the umami by seven to eight times, making food naturally more delicious and satisfying simply by incorporating basic dashi stock.
- ½ oz (15 g) kombu
- ½ oz (15 g) katsuobushi
- 4 cups (1000 ml) water
1. Gently clean the surface of the kombu with a dry towel. Do not remove or wash off the white powdery substance on the surface of kombu, which is a source of umami flavorcalled mannitol.
2. Soak the kombu in the water in a small saucepan for at least 15 minutes, or more, at room temperature.
3. Heat the kombu (in the same saucepan with the soaking liquid) over medium-low heat just until you start to see small bubbles around the edge of the pot (150 degrees Fahrenheit/ 65 degrees Celsius). Make sure not to boil the water.
4. Remove the kombu from the saucepan.
5. Add the katsuobushi to the saucepan and turn off the heat.
6. Let the katsuobushi sit for 2 to 3 minutes.
7. Line a colander or a strainer with a layer of paper towel and place in a bowl. Strain the broth without squeezing the katsuobushi. Store in a resealable plastic bag in the refrigerator for 2 days, or in the freezer for up to 1 month. You can reuse the kombu and katsuobushi by repeating the same process one more time, as with the second brew, by adding an additional ¼ oz (10 g) katsuobushi to the pot.
Tips on how to repurpose leftover kombu and katsuobushi
The kombu will expand as much as three to four times its volume after being soaked in water Stack a few pieces of kombu, tightly roll, and cut them into thin strips and add to stir-fries and soups. (recipe#15, 61) Or, store the leftover kombu in a resealable plastic bag in the freezer until you need it, for up to one month. You can also reuse the kombu and katsuobushi by repeating the same process one more time as with the second brew dashi stock by adding an additional ¼ oz (10 g) katsuobushi to the pot. Second dashi stock has a less intense flavor, but is still a good soup base for noodles, simmered dishes and miso soups.
Tips on selecting & how to store kombu
The best kombu for cooking is known to be thick, aromatic, and well-dried. The best way to preserve Kombu is to store it in an air-tight container or resealable bags in a cool, dry place away from heat and moisture.
When using longer pieces of Kombu, we recommend trimming to about 5 to 6 inches (12.75 to 15 cm) for easy cooking. The shelf life for dried seaweed is approximately one year.