The Japanese Sweet, which may also be referred to as a Japanese yam, an Oriental, Kotobuki, Satsuma Imo, or Satsumaimo, is a variety of potato that is common in Japan and is now grown in the U.S. as well as many other regions of the world. A light red to deeper red outer skin color covers a dense flesh that has a low moisture content. Unlike some potatoes that become brown after they have been peeled, the Japanese Sweet Potato can be cut or cubed and left standing for a half hour a little longer without browning. However, removing the skin prior to cooking improves the flavor of this potato since the skin has a somewhat bitter flavor. It is an excellent choice to cube for roasting, steaming or stir-frying because it can be cooked quickly at a higher heat setting more effectively than other varieties that do not cook as well when using faster cooking methods.
The Japanese Sweet Potato and the Japanese Yamaimo (Mountain Yam) are often confused as being the same potato however, they are two different tubers. The light tan outer skin color of Yamaimo is similar to a baking potato and differs in appearance from the reddish-pink skin coloring of the Japanese Sweet. The Japanese Yamaimo is a somewhat sticky, mountain yam which is the variety often used to make soba noodles.