The thin Japanese buckwheat noodles are called soba. Made primarily from buckwheat flour, soba usually has a distinctive gray-brown color and slightly grainy texture, though wheat flour is often blended in to make the dough easier to handle.
Soba can be served hot in a broth or chilled with a dipping sauce. Popular varieties include zaru soba, served cold on a bamboo tray, and kake soba, served in hot soup. Ni-hachi soba traditionally contains about 80% buckwheat and 20% wheat, while juwari soba is made entirely from buckwheat.
Buckwheat cultivation in Japan dates back thousands of years, and records specifically mentioning buckwheat noodles appear by 1574. Soba became especially popular among ordinary people during the Edo period. It is easy to confuse soba with somen, ramen, or udon, but those are generally wheat-based noodles. Yakisoba is another common trap: despite its name, it usually uses wheat-based Chinese-style noodles rather than buckwheat soba.