Good stock is crystal clear, without a trace of oil or fat. It is a subtle blend of flavor, smoky yet sweet, with a hint of the salty sea. It is made from konbu (dried cultivated kelp) and katsuo bushi (dried bonito), both of which may appear unappealing to the uninitiated. Konbu is a sturdy sea plant which, when dried, resembles strips of dark, dusty leather. It imparts a mellow sweetness to the stock that no other ingredient could. Katsuo bushi looks like sawdust or wood shavings and smells a bit fishy too. Yet these flakes of dried bonito lend a subtle smoked flavor and aroma to the final stock.
The essence of good stock making is timing. If the konbu is allowed to boil, the broth will be bitter and cloudy. If the katsuo bushi is not strained out within a few minutes, the stock will indeed taste fishy. Dashi making, though, is not the time-consuming process that stock making often is in the West. From start to finish, it should take no more than ten minutes. Leftover dashi may be refrigerated for up to 4 days, but its delicate flavor does not hold up to freezing.
Place the kelp in a large saucepan, measure in the cold water and bring it to a boil over high heat. Remove the kelp immediately. (Note: several recipes make use of softened kelp and it can be stored in the refrigerator for several days.) Take the saucepan from the heat. Add the bonito flakes and let them settle to the bottom of the broth naturally.
Then line a colander with a finely woven white cloth and strain the stock through it. Gather up the edges of the cloth to make a bag, twisting and gently squeezing it. Discard the water-logged bonito flakes.
© 1986 Elizabeth Andoh. All rights reserved.