Buckwheat noodles called soba and another type of noodles made from flour called udon are the most popular varieties of Japanese noodles. Buckwheat noodles are made from buckwheat flour and a small quantity of other ingredients such as wheat flour, grated yam, and egg white, which are added to make the buckwheat stick together. Salt and water are then added to make dough. Next the dough is kneaded, rolled thinly with a rolling pin, and then cut into thin strips. Buckwheat noodles are generally light brown due to the color of the buckwheat flour, but there are also green noodles called chasoba. Cha means tea and the color of the green noodles comes from a small quantity of tea that is added to the dough.
First the buckwheat noodles are boiled and then they are eaten with tsuyu. Tsuyu is a broth seasoned with soy sauce and another seasoning called mirin that contains sweet sake and other ingredients. There are two ways to eat the buckwheat noodles. One way is called kakesoba, which means that the noodles are served right after being boiled and eaten in a hot broth while the noodles are still hot. The other way is called zarusoba, which means that the noodles are chilled in cold water first. Then the person eating dips the noodles in a cold broth and eats them. Noodles can be eaten simply in a broth garnished with small quantities of condiments such as scallions, red pepper, and wasabi (Japanese horseradish). People often eat soba, however, with their favorite ingredients such as deep fried tofu (bean curd), prawn tempura, and raw eggs. Buckwheat noodles are very popular in Japan and people often prefer them when they would like a light meal. Soba is especially popular for lunch.