The Japanese noodle dish made from buckwheat flour and often served cold with dipping sauce is soba.
Soba noodles are made primarily from buckwheat flour, often blended with wheat flour to improve elasticity. They have a characteristic brown-gray color and slightly grainy texture. In Japan, soba may be served chilled on a bamboo or woven tray with a concentrated dipping sauce called soba tsuyu, or hot in a soy-and-dashi broth.
Cold zaru soba is dipped a little at a time into tsuyu, which is commonly seasoned with dashi, soy sauce, and mirin. Wasabi and sliced negi, or Japanese green onion, are frequent accompaniments. Slurping noodles is socially acceptable in Japan and can help draw them quickly into the mouth while cooling them.
Soba has a long history in Japan. Buckwheat was cultivated there by the Jōmon period, and a record from 1574 specifically mentions soba-kiri, or sliced buckwheat noodles. Soba is often confused with udon or ramen, but those noodles are wheat-based; shirataki is made from konjac and has a translucent, gelatinous texture.