Some people believe that Soba should be black and white one is mixture of something.
It may be true if we are living in the time when we can grind only with millstone. Now is the time, however, that both guest and cook can choose between white flour and black one, as we can select the flour type by demand-stage.
Black flour is strongly scented with rustic flavor. It is often used for Futo-uchi Soba (thick soba noodles) such as Inaka-soba.
White Soba, on the other hand, has a clean finish and a delicate taste. It is used for Hoso-uchi Soba (thin soba noodles).