The tops of the plants above ground can be eaten as greens.
The actual potatoes have buff skin, darkening when cooked. Inside, the flesh is light purple, turning brilliant purple when cooked.
The taste, despite the purple colour, is very similar to that of normal sweet potatoes.
Large-sized ones will be around 1 1/2 pounds (750g.)
The potatoes can be cooked in almost any way. Some say they are best roasted or baked. But they are also processed into chips, dried into flakes, sliced, battered and fried and served as tempura, or mashed and mixed with ginger and served as “dessert.”
Avoid ones that smell mouldy or musty.
Cook the potatoes soon after cutting them open, or the flesh will turn greyish-brown from exposure to the air.
Store in cool, dry place. If you refrigerate them, do so for no more than 5 days.
Okinawan Sweet Potatoes were introduced into Japan from China sometime in the 1600s.