Two humble potatoes, preserved in a ceramic jar buried for five centuries, tell a story of ingenuity, logistics, and the deep roots of Andean agriculture. Archaeologists working at Tambo Viejo, an Inca center in Peru's Acarí Valley, recently unearthed these 500-year-old freeze-dried potatoes—among the only ones found in more than a century—and in doing so uncovered tangible evidence of how the Inca moved food across one of history's most formidable empires.
The potatoes, known as chuño, represent far more than a archaeological curiosity. They are a window into the ingenuity of ancient Andean peoples and a testament to the sophisticated supply chains that sustained the Inca workforce across mountains and deserts. In the 15th and 16th centuries, when these potatoes were processed and stored, they were quite literally the bread of the people—lightweight, durable, and capable of lasting for years without spoiling, making them ideal for feeding armies, workers, and entire regions.
Dr. Lidio Valdez, an archaeologist at the University of Calgary, led the 2024 excavations at Tambo Viejo. His team discovered the two brownish-white chuños inside a storage jar set directly into the floor, alongside a broken piece of Inca pottery and a damaged spindle whorl. That everyday detritus proved crucial: it confirmed beyond doubt that these potatoes dated to Inca times, not some later period. "It was obvious that this was not just any find, but a special one," Valdez recalled upon discovery, telling his field team: "Here we have an article."
The creation of chuño itself reveals the resourcefulness of Andean farmers. Potatoes are native to the Andes but spoil easily in warm climates—some varieties are even bitter and toxic without processing. The Inca solved this problem through a process that required the freezing peaks of the mountains. Fresh potatoes were exposed to extreme winter frosts at high altitude, thawed in the intense daytime sun, and this cycle repeated until the potatoes could be trampled and dried. The result came in two forms: black chuño from regular potatoes, and white chuño—the kind found at Tambo Viejo—made from naturally toxic varieties that required weeks of soaking before drying.
The presence of chuño on Peru's arid coast is itself remarkable. Because chuño can only be made in the freezing mountains, its discovery at a coastal site provides physical proof of the Inca's vast trade networks. Spanish chroniclers documented that llama caravans hauled chuño and other foods to storage houses scattered across the empire, feeding the Inca workforce wherever it labored. Some foods were so valuable that Spanish conquistadors grew wealthy simply by reselling chuño in the mines after the Inca fell.
Yet chuño rarely survives in archaeological contexts. The only other comparable discovery happened more than a century ago at Pachacamac, Peru. The arid coastal environment and the protection of the storage jar likely saved these two potatoes from decomposition, allowing them to endure into the modern era. Their rarity means they have been largely overlooked by researchers studying Indigenous staples, despite their crucial role in feeding an empire.
Valdez and his team hope to conduct chemical analysis to trace exactly which Andean mountains produced these potatoes. For now, Tambo Viejo remains unique among Inca sites, and Valdez plans to return. "Every single dig produced wonderful results," he said—a reminder that sometimes the most profound historical truths hide in plain sight, waiting beneath five centuries of sand.