Dried red sweet potatoes use Oki Yume Purple, which is an encouraged variety of Okinawa Prefecture. Oki Yumeshi has a sweeter taste than red sweet potatoes for processing such as Chura Koi Beni, and is mainly used for fruits and vegetables. Dried sweet potatoes are aged in a refrigerator with a temperature of around 13°C and a humidity of around 90% for 40 to 60 days to increase the sugar content. Then take it out of the refrigerator, steam it, peel it and slice it into slices about 1 cm thick. After slicing, it is placed in a dryer and dried at a temperature of 50°C for 6 hours. The dried red sweet potatoes have a sugar content of 50 to 60 degrees, allowing you to taste the sweetness and flavor of sweet potatoes.