Dashi is a class of soup and cooking stocks considered fundamental to Japanese cooking. In 1980, Shizuo Tsuji wrote:
"Many substitutes for dashi are possible, but without dashi, dishes are merely a la japonaise and lack the authentic flavour."
Dashi forms the base for miso soups, clear broths, noodle broths, and many simmering liquids.
The most common form of dashi is a simple broth or stock made by heating water containing kombu (edible kelp) and kezurikatsuo (shavings of katsuobushi - preserved, fermented tuna) to near-boiling, then straining the resultant liquid.
Fresh dashi made from dried kelp and katsuobushi is rare today, even in Japan. Most people now use granulated or liquid instant substitutes.
Other kinds of dashi stock are made by soaking kelp, niboshi, or shiitake in water for many hours or by heating them in near-boiling water and straining the resultant broth.
- Kombu dashi stock is made by soaking kelp, or sea tangle, in water.
- Niboshi dashi stock is made by pinching off the heads and entrails of small dried sardines, to prevent bitterness, and soaking the remains in water.
- Shiitake dashi stock is made by soaking dried shiitake mushrooms in water.