When archaeologists unearthed two small, wrinkled potatoes at the Tambo Viejo site in Peru's Acarí Valley, they weren't just finding ancient food — they were uncovering evidence of one of history's most effective food storage and distribution systems.
The potatoes, called chuño, date back roughly 500 years to the Inca Empire. What makes them remarkable is their excellent state of preservation, a testament to a system so effective it sustained one of history's most ambitious civilizations.
Lidio Valdez, an archaeology professor at the University of Calgary who led the excavation, explained the Inca approach to food preservation. "Freeze-dried potatoes can be produced only at high elevations," he noted. "Afterward, the chuño were stored in state-controlled warehouses, most of them built also at high elevations."
The Inca engineered an entire supply chain. Potatoes were cultivated at scale, processed through freeze-drying at optimal elevations, then distributed through llama caravans to administrative centers like Tambo Viejo, where they were placed in ceramic vessels and stored underground.
This was state-level food infrastructure designed to support thousands of workers across massive construction projects: palaces, roads and Machu Picchu itself. The people who built the empire, Valdez stressed, literally lived off chuño.
Potatoes have high water content, which means they spoil quickly in humid environments. "Place a potato somewhere in your kitchen just for a month and see what will happen," Valdez said. "In places with rain and moisture, potatoes will rot quickly. Therefore, freeze-drying was and is an effective way to preserve and store them for long periods of time."
Freeze-drying works in the Andes because of the region's aridity and elevation. It wasn't imposed from outside; it was adapted to place. The warehouses were built at high elevations where conditions naturally supported storage. The distribution network relied on llama caravans, an animal perfectly suited to mountain terrain.
Tambo Viejo itself illustrates this principle. As an administrative center, it served as a hub in this larger network — a place where food from across the empire could be received, stored and redistributed according to state needs.
Valdez initially came to Tambo Viejo hoping to learn more about khipus, the Inca recording system. Instead, he found physical evidence of how an empire fed itself. "Almost everything found at the site is unprecedented," he said, describing it as "such a unique center."
Despite centuries underground, the potatoes retained their shape and color. The only visible change was a reduction in size, likely due to the region's aridity over time. There is, Valdez observed, no way to tell their age simply by looking at them — a reminder that ancient peoples possessed preservation knowledge largely abandoned today.
Valdez's excavation, which has been ongoing since 2018, continues to yield discoveries. Each find adds texture to understanding how the Inca actually lived and worked — as people solving real problems of production, preservation and distribution.
