Protected local food
Namegata Kansho
行方かんしょ
Very sweet sweet potatoes from around Lake Kasumigaura in Ibaraki. Namegata is the top single supplier to Tokyo's markets and helped make roasted sweet potato a supermarket staple.
Key facts
- Registered as a protected name
- 31 March 2023
- Region
- Kanto
- Official name in Japanese
- 行方かんしょ
- Official area (in Japanese)
- 行方市、潮来市、鹿嶋市、鉾田市、小美玉市、かすみがうら市
Japan's sweet potato heartland
Namegata sweet potatoes come from six cities around Lake Kasumigaura in Ibaraki: Namegata, Itako, Kashima, Hokota, Omitama and Kasumigaura. The mild climate and well-drained soil suit sweet potatoes, and around 1945 the area grew more of them than anywhere else in Japan. Today it ships more than any other single shipping point to the Tokyo markets.
Cured, stored and sweet
Growers cure the potatoes after harvest, then store them at a constant temperature, which builds sweetness. They also ship different varieties one after another through the year, so the potatoes taste their best whenever you buy them.
The yaki-imo strategy
Namegata wrote a roasting manual and worked with big supermarket chains to roast sweet potatoes in store. Those warm, sticky-sweet yaki-imo by the checkout helped push sweet potato sales up across Japan.
Good to know
- Buy a hot yaki-imo from a Japanese supermarket in autumn or winter. It is an easy, cheap snack.
- Itako, one of the growing cities, is known for its iris festival and boat rides in early summer.
Questions travellers ask
What is kansho?
The formal Japanese word for sweet potato, also called satsumaimo.
When is the best season?
Harvest is in autumn, but cured and stored potatoes taste sweetest in winter.
Where it comes from
More protected foods from the same area
Crafts from the same area
Heritage stories from the same area
Sources
We checked the facts on this page against these sources.