In olden days, charcoal production flourished in Noto, and ash taken from the kiln and straw ash were used to cover wakame seaweed when it was being sundried on the beach. This technique was created in the Edo period, and it can keep the color and texture of seaweed for more than one year at normal temperature. It is because the alkali in ash hinders the effect of enzymes and keeps its bright green color. The ash also prevents deterioration of seaweed by absorbing water on the seaweed’s surface and drying it quickly. The ash also contains much calcium, which prevents the seaweed from softening and maintains its natural texture. Another type of seaweed called “sea noodle” is also processed in the same way. These seaweed products are the specialty of Noto.