By Hideo Dekura, Brigid Treloar, Ryuichi Yoshii, Authors of The Complete Book of Sushi
Traditional dashi is made with bonito fish that has been smoked, dried and fermented for several months. The hard bonito is shaved into flakes on a wooden block and simmered in water with a piece of kombu, or dried kelp. People generally use already prepared bonito flakes these days. We recommend making your own dashi using the traditional methods and ingredients because of the quality of the final stock, but as bonito flakes are not cheap and making dashi takes time, instant dashi (hon dashi) may be substituted.
Makes 4 1/2 cups (36 fl oz/1.1 L)
4 1/2 cups water
1 kombu, 4-inch square
1/2 oz bonito flakes
Use a clean, damp cloth to wipe off white film on surface of kombu. In a saucepan, combine water and kombu. Let soak for up to 2 hours, then place over high heat and bring to a simmer. When stock begins to bubble slightly, after about 5 minutes, check center of kombu. If it is soft, remove kombu from saucepan and set aside. If it is hard, continue cooking for a few more minutes, then remove. Let mixture come to boil, then stir. Skim off any bubbles or scum on surface.
Remove from heat and add a small amount of cold water to lower temperature before adding bonito flakes. (Boiling water makes them smell.) Add bonito flakes to saucepan. Do not stir. Use chopsticks to press the flakes down gently to bottom of saucepan. Let rest for 3 minutes.
Lay cheesecloth or a clean napkin over a colander and strain mixture into a large bowl to remove bonito flakes. Remove the drained bonito flakes and reserve.
If, after tasting the finished dashi, you wish to strengthen its flavor, return mixture to saucepan and simmer for another 5 minutes.
Reprinted with the express permission of Tuttle Publishing, a member of the Periplus Publishing Group.