Yamadai Kansho sweet potatoes have been cultivated in Kushima City, in southern Miyazaki Prefecture, since the 1960s (the Showa 40s in Japan).
The area has broad upland fields with plenty of sunshine and well-drained volcanic ash soil containing iron. These natural conditions are well suited to sweet potato cultivation, and production quickly became established in the region.
Today, Yamadai Kansho is recognized as a distinctive Kushima brand, with production volumes ranking among the highest in Japan.
The sweet potatoes used for Yamadai Kansho are of the Miyazaki Beni variety. They are grown from healthy, virus-free seedlings, with careful attention paid to the quality of the plants from the beginning of cultivation.
After harvesting, the sweet potatoes are stored for 60 to 90 days in a storage facility maintained at approximately 13°C. This period of controlled storage helps increase their sugar content and develop their flavor.
The finished sweet potatoes are known for their rich aroma and pleasantly fluffy texture, together with a satisfying natural sweetness. Their full-bodied flavor makes them delicious when simply cooked and enjoyed on their own.