are very thin, white Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese noodle

Noodle

The noodle is a type of food, made from any of a variety of doughs, formed into long thin ribbons, strips, curly-cues, waves, helices, pipes, tubes, strings, or other various shapes, sometimes folded. They are usually cooked in a mixture of boiling water and/or oil. Depending upon the type, noodles...

s made of wheat flour

Wheat flour

Wheat flour is a powder made from the grinding of wheat used for human consumption. More wheat flour is produced than any other flour. Wheat varieties are called "clean," "white," or "brown" if they have high gluten content, and they are called "soft" or "weak" flour if gluten content is low...

. The noodles are usually served cold and are less than 1.3 mm in diameter. The distinction between sōmen and the next thicker wheat noodles hiyamugi and even thicker Japanese wheat noodles udon

Udon

is a type of thick wheat-flour noodle of Japanese cuisine.Udon is usually served hot as noodle soup in its simplest form as kake udon, in a mildly flavoured broth called kakejiru which is made of dashi, soy sauce , and mirin. It is usually topped with thinly chopped scallions...

is mostly the size of the noodle. Somen noodles are stretched when made, as are some types of udon noodles.

Sōmen are usually served cold with a light flavored dipping sauce or tsuyu. The tsuyu is usually a katsuobushi

Katsuobushi

is the Japanese name for dried, fermented, and smoked skipjack tuna .Shaved Katsuobushi and dried kelp - kombu - are the main ingredients of dashi, a broth that forms the basis of many soups and sauces in Japanese cuisine.Katsuobushi's distinct umami flavor comes from its high...

-based sauce that can be flavored with Welsh onion

Welsh onion

Allium fistulosum L. is a perennial onion. Other names that may be applied to this plant include green onion, spring onion, escallion, and salad onion...

, ginger

Ginger

Ginger is the rhizome of the plant Zingiber officinale, consumed as a delicacy, medicine, or spice. It lends its name to its genus and family . Other notable members of this plant family are turmeric, cardamom, and galangal....

, or myoga

Myoga

Myōga or myoga ginger is an herbaceous, deciduous, perennial native to Japan and southern part of Korea that is grown for its edible flower buds and flavorful shoots. Flower buds are finely shredded and used in Japanese cuisine as a garnish for miso soup, sunomono and dishes such as roasted...

. In the summer, sōmen chilled with ice is a popular meal to help stay cool.

Sōmen served in hot soup is usually called "nyumen" and eaten in the winter, much like soba

Soba

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 . Soba noodles are served either chilled with a dipping sauce, or in hot broth as a noodle soup...

 or udon are.

Nagashi sōmen

Some restaurants offer "nagashi sōmen" (流しそうめん flowing noodles) in the summer. The noodles are placed in a long flume of bamboo

Bamboo

Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....

 across the length of the restaurant. The flume carries clear, ice-cold water. As the sōmen pass by, diners pluck them out with their chopsticks

Chopsticks

Chopsticks are small, often tapered, sticks used in pairs of equal length as the traditional eating utensils of China and its diaspora, Japan, Korea, Vietnam and Northern provinces of Laos, Thailand and Burma. Generally believed to have originated in ancient China, they can also be found in some...

and dip them in tsuyu. Catching the noodles requires a fair amount of dexterity, but the noodles that are not caught by the time they get to the end usually are not eaten, so diners are pressured to catch as much as they can. A few luxurious establishments put their sōmen in real streams so that diners can enjoy their meal in a beautiful garden setting. Machines have been designed to simulate this experience at home.