Zaru soba is the Japanese noodle dish consisting of cold soba served on a bamboo tray with a separate dipping sauce.
The name refers to the zaru, a traditional bamboo draining tray on which the chilled noodles are presented. The soba is made primarily from buckwheat, though some varieties contain wheat flour to improve elasticity. Diners lift a portion of noodles and dip it briefly into tsuyu, a savory sauce usually based on soy sauce, dashi, and mirin.
Common accompaniments include grated daikon, wasabi, sliced scallions, and shredded nori. The noodles are rinsed after cooking, which removes excess surface starch and gives them a clean texture.
Zaru soba differs from kake soba, in which soba is served in a hot broth. Mori soba is also cold soba, but the name does not specifically emphasize presentation on a bamboo zaru.