an ancient process devised by the peruvians is the preservation of potatoes by "freeze-drying" them for future use. first, the potatoes were spread-out under the sun during the dry months of june and july, which are also the coldest months in peru. for a period of 3 to 4 days, the potatoes were exposed to hot temperatures during the day, and below 0° degree temperatures at night, until one was left with "chuño" - a natural crisp potato. this exposure to the heat and the cold made them naturally "freeze- dried." during the drying process, at the end of each day the potatoes were crushed to extract their liquid, and frozen all over again at night. this process was repeated several times until the potatoes were completely dehydrated. after drying, the dry potatoes would be trodden under foot to loosen their skins, and the skins were eventually peeled-off by hand. after peeling, the potatoes were placed inside a reed-like basket, and the basket inserted into running river water, whose waters were very cold, and left there for about 3 weeks. afterwards, the "moraya" was collected, dried, and then pounded into a flour. the flour could last up to 4 years, without spoiling. the peruvians made a soup from the "moraya" flour, mixed with garlic, fresh potatoes, carrots and onions. the "huatia" oven, or an earthenware oven, were traditionally used for cooking the "moraya" soup.