Imakane Danshaku

Imakane Danshaku is a variety of potato with starch content more than 13.5% and with a bright white skin.
　It is characterized by stable quality and a silky-smooth, creamy mouthfeel.
　Owing to strict grading standards, Imakane Danshaku are uniform in size and shape with white skin. Vegetable markets rate Imakane Danshaku as top-class in quality and taste, and sell it at prices 20% or more higher than Danshaku ⁽¹⁾ potato varieties from other areas.

For the production of Imakane Danshaku, as its name suggests, disease-free seed potatoes of the Danshaku variety, grown by seed potato farmers, are used.
　Samples are measured before harvesting, and potatoes are only harvested in fields where samples have reached the Lyman value criteria of 13.5% or higher.
　Potatoes are air-dried in storage for about one week before shipping to prevent rotting and peeling. When shipping, the quality is checked by hollow inspection.
　Potatoes confirmed to have deteriorated quality due to peeling or scratching cannot be shipped as Imakane Danshaku.

The producing area is located in the northern part of Oshima Peninsula ⁽²⁾. The area has inland climate with big temperature difference between daytime and nighttime, and well-drained, fertile volcanic ash soil, which is suitable for potato cultivation.
　Since 1953, farmers in the area have cultivated only the Danshaku variety, with efforts to improve quality, such as separating food potato farmers from seed potato farmers, being continued since 1967.
　Hollow inspection was adopted in 1989, and further improvements in the shipping system were pursued including the establishment in 1994 of shipping standards requiring that shipping only potatoes meet the prescribed Lyman value.
　As of 2017, the production area totals 375 ha yielding 12,000 tons. Although the yield is smaller than other potato production areas in Hokkaido, production is increasing every year.

1. Danshaku potato: In 1908, Baron (Danshaku) Ryukichi Kawata from Kochi Prefecture conducted trial cultivation of a potato variety native to America in Kamiiso Town, Hokkaido. The variety was hence named Danshaku in Japan. Danshaku soon spread as a superior variety, and is now a representative variety accounting for about 20% of domestic potato production.
2. Oshima Peninsula: Extending from the western part of Hokkaido and forking southwards, this peninsula has multiple volcanoes. Even in the Edo Period, when Hokkaido remained mostly unexplored, a domain (han) was located in Oshima Peninsula, making it the most populated area in Hokkaido until the Meiji Period.