Wikipedia Article About Somen on Wikipedia
Sōmen (Japanese: 素麺, そうめん) are very thin, white Japanese noodles made of wheat flour. The noodles are usually served cold and are less than 1.3 mm in diameter. The next thicker wheat noodles are called hiyamugi and even thicker Japanese wheat noodles are called udon.
Sōmen are usually served cold with a light flavored dipping broth or tsuyu, and noodles are dipped into the sauce, not poured over like other foods. The sauce is usually a katsuobushi based sauce that can be flavored with Welsh onion, ginger, or myoga. In the summer time sōmen chilled with ice is a popular meal to help stay cool. Somen served in hot soup is usually called "nyumen," and is frequently served in the winter much like soba or udon would be.