Chuño

Chuño is a traditional Andean food preservation technique, and the resulting product, in which small bitter native potato varieties (especially those from the altiplano of Bolivia and Peru at altitudes above 3,800 m / 12,500 ft) are transformed into shelf-stable, completely dehydrated pellets through a multi-day cycle of natural freeze-drying. The process exploits the extreme temperature swings of the high Andes: potatoes are spread on the ground at night, where temperatures regularly fall to −5 °C to −15 °C (23 °F to 5 °F), freezing the potato cells and rupturing them. During the day, intense equatorial sunlight at altitude evaporates the thawed moisture. After several freeze-thaw-evaporation cycles over three to five days, the potatoes are additionally stomped by foot (a step called 'trampling' or pisado) to press out remaining moisture and loosen the skin. The result is a hard, light, chalky-white or blackish pellet (depending on variety and process) that has lost 80–85% of its original weight and virtually all water. Black chuño (chuño negro) is made without any washing, producing a more intense, slightly bitter, earthy flavor. White chuño — called tunta or moraya — is made by additionally soaking the frozen potatoes in a running stream for two to four weeks before final drying, which removes bitter glycoalkaloids (solanine) and produces a milder, chalky-white pellet with a starchy, neutral flavor. Chuño can be stored for years to decades without refrigeration, and historically formed the strategic food reserve of the Inca Empire, enabling populations to survive drought, famine, and the agricultural demands of road-building. To cook, chuño is soaked in water for several hours or overnight until rehydrated, then simmered in stews (chairo, locro) or ground into flour.

“She dropped a handful of black chuño into the simmering pot of chairo, where it swelled and absorbed the lamb broth, its earthy, concentrated flavor deepening the stew.”

• IngredientNative Andean Potato
• TechniqueFreeze Drying
• CuisinePeruvian

1. 1.The Oxford Companion to Food — Alan Davidson (3rd ed., 2014)
2. 2.Andean Roots and Tubers: Ahipa, Arracacha, Maca and Yacon — M. Hermann & J. Heller (eds.), IPGRI 1997
3. 3.Eight Flavors: The Untold Story of American Cuisine — Sarah Lohman (context on global preserved starches)
4. 4.Cocina Andina — Sergio Zapata Acha
5. 5.Peru: The Cookbook — Gastón Acurio

Confidence: high