Scientists Bake Sourdough With 5,300-Year-Old Yeast From Ötzi

Scientists just baked sourdough bread with yeast that's been frozen for over 5,000 years, and it might actually help solve modern food production challenges.

When hikers discovered Ötzi the Iceman's mummified body in the Tyrolean Alps in 1991, nobody imagined his remains would still harbor living microorganisms. But researchers at Eurac Research's Institute for Mummy Studies found something remarkable: four strains of cold-adapted yeast still clinging to the 5,300-year-old body.

Mohamed Sarhan and Frank Maixner's team defrosted Ötzi in April 2019 for the first time in decades, keeping him at 39 degrees for five hours. They carefully collected ice samples, swabbed his body, and analyzed the water that pooled around his remains.

The analysis revealed a fascinating mix of ancient and modern microbes. Some likely lived inside Ötzi when he was alive, while others colonized his body after death or arrived during conservation work over the years.

The real surprise came when comparing samples from 2010 and 2019. One yeast strain called Glaciozyma had grown to become the dominant microorganism on the body, suggesting these tiny organisms remained active throughout the millennia.

Sarhan and his colleagues decided to put the ancient yeast to the test. They successfully baked sourdough bread, and now they're planning to try brewing beer next.

The Bright Side

These cold-loving yeasts could revolutionize how we make food. Unlike modern yeasts that need warmth to work, Ötzi's ancient strains can ferment at room temperature or even refrigerator temperatures.

That means bakers and brewers could save significant energy by skipping the heating process. The yeasts could even start fermenting during transport, making production more efficient from the moment ingredients leave the farm.

"Yeasts that are active at very low temperatures can offer advantages in different areas," Sarhan explains. The team is now working with food industry specialists to explore practical applications.

The research also helps preserve one of archaeology's most important discoveries. By understanding which microbes live on Ötzi's body, scientists can better protect his remains for future generations to study.

Patrick Hunt, an alpine archaeologist at Stanford, calls Ötzi "the most important archaeological science finding of the 20th century," making preservation efforts critical. The team found no evidence the microbes are harming the body, but they plan additional studies to monitor long-term effects.

From ancient glacier to modern bakery, these tiny organisms prove that even after 5,000 years, the past still has practical gifts to offer our future.