Chuño and Tunta

chuño and tunta two dried potato products developed in the foothills of the Andes in S. America over 2,000 years ago. Dawn and Douglas Nelson (1983) believe that the process must have been discovered accidentally and that it was only in the Andes that the necessary climatic conditions existed; these were that every autumn should have long periods of sub-zero temperatures at night followed by bright sunshine and drying winds during the day. The Nelsons point out that the varieties of potato used are almost tasteless and are reserved for this purpose. They continue:

The freshly lifted potatoes are washed clean without damaging the skins and laid out on soft turf or straw padding to be exposed to severe night frost. As soon as they have thawed in the morning they are trodden with bare feet so that the skin remains intact but the fluid resulting from cell rupture is extruded. On the first pressing over 30 per cent of the fluid may be lost. They are left in position and dried by the sun and wind. The process is repeated for five successive days. From the sixth day onwards no further pressing takes place and they are straw-covered to a sufficient depth to prevent further freezing at night. Once dried they are as hard as stone and can be stored indefinitely, and even a minor degree of damp does not seem to damage them unduly. This product is called chuño.