Soba (そば) is the Japanese name for buckwheat. It is synonymous with a type of thin noodle made from buckwheat flour, and in Japan can refer to any thin noodle (unlike thick wheat noodles, known as udon). Soba noodles are served either chilled with a dipping sauce, or in hot broth as a noodle soup. It takes three months for buckwheat to be ready for harvest, so it can be harvested four times a year, mainly in spring, summer, and autumn. In Japan, buckwheat is produced mainly in Hokkaido. Soba that is made with newly harvested buckwheat is called "shin-soba". It is sweeter and more flavorful than regular soba.
Begin Japanology - Soba by Best of Japan.