Kanten is a food product made from seaweed. Because adding water produces a jelly at room temperature, it was historically an important ingredient in Japanese recipes, especially desserts. It's now prized as a health food, vegetarian and rich in fiber. The traditional way of making kanten is still used in the Suwa area of Nagano. Local daily temperature variations enable repeated natural freezing and drying. It takes about two weeks to produce kanten famed for its pleasing texture.
VIDEO BY MINISTRY OF FOREIGN AFFAIRS OF JAPAN