Archaeologists in Peru have discovered freeze-dried potatoes, known as chuño, that are approximately 500 years old, predating the founding of the United States. The remarkably well-preserved specimens were found at the Tambo Viejo site in the Acarí Valley.
The discovery, detailed in the Journal of Field Archaeology, provides evidence of advanced food preservation techniques employed by the Inca Empire. According to Lidio Valdez, an archaeology professor at the University of Calgary who led the excavation, the freeze-dried potatoes retain their shape and color, appearing strikingly similar to modern produce despite their age.
Valdez noted that while the samples are smaller than their original size, their excellent state of preservation highlights the effectiveness of ancient Andean methods. Freeze-drying is particularly crucial for potatoes, which have a high water content and quickly rot in humid environments. "Freeze-dried potatoes can be produced only at high elevations," Valdez explained. "Afterward, the chuño were stored in state-controlled warehouses, most of them built also at high elevations."
The Inca likely transported these chuño over long distances to feed workers involved in state projects. "Because the Inca state carried out countless projects throughout the realm, the tasks involved thousands of workers, who had to be fed by the state," Valdez said. "Thus, state officials likely mobilized volumes of chuño from the warehouses, transporting them in llama caravans."
At Tambo Viejo, the potatoes were stored in ceramic vessels and placed underground to prevent spoilage. Valdez emphasized that chuño was a staple food for the Inca, sustaining the people who built significant structures like Machu Picchu. "It appears that in Inca times, large volumes of potatoes were cultivated and freeze-dried, then stored in state-controlled warehouses."
Tambo Viejo, an administrative center, has been excavated intermittently since 2018 and has yielded numerous unprecedented discoveries, making it a unique archaeological site. This find contributes to a growing body of evidence revealing the sophisticated food practices of ancient civilizations, similar to preserved food remains found in Pompeii and ancient bread discovered in Switzerland.