Kankoro mochi (かんころもち, the kanji representation 甘古呂餅 is a registered trademark) is a type of mochi mixed with parboiled sweet potato. It is a regional cuisine and wagashi originating from the Gotō Islands in Nagasaki Prefecture.
It is manufactured throughout Nagasaki Prefecture, mainly in Gotō, Saikai, and Sasebo.
"Kankoro", in Gotō's regional dialect, refers to thinly-sliced, sundried sweet potato.[1] Originally prepared as a non-perishable food for winter in the Gotō region, it has become a specialty, or tokusanhin, of Nagasaki Prefecture and is manufactured and sold throughout the prefecture.
Sweet potatoes can be grown on the Gotō Islands despite its lack of flat ground and abundance of barren slopes. Additionally, there is little difference between a good and bad harvest, and they are resistant to damage from typhoons, eliminating the risk of famine. These qualities have made sweet potatoes valued as a vital agriculture product supporting the economy of the Gotō Islands.Although it is unknown when sweet potatoes came to be cultivated on the Gotō Islands, it had become a crop grown by commoners by the Kanbun era (1661–1672), and in 1833, the Fukue Domain began to promote sweet potato cultivation in a dramatic shift from existing regulations. Sweet potatoes began to spread across the islands at the beginning of the Meiji era in the late 1860s, and by the Taishō era (1912–1926), it was the Gotō Islands' most abundant agricultural product.
Cultivation of sweet potatoes in Gotō would later slowly decline as their demand as an ingredient in shōchū and starch waned. However, many households still make kankoro mochi for the Japanese New Year to send to children and relatives who have left the islands.