Scientists Bake Sourdough Using Yeast From 5,300-Year-Old Mummy

Scientists extracted living yeast from the digestive system of a 5,300-year-old mummy found in the Alps and used it to create sourdough bread, according to a study published Wednesday in the journal Microbiome. The mummy, discovered by hikers in 1991 on the border between Austria and Italy, had remained frozen at minus six degrees Celsius since his death by arrow wound more than five millennia ago.

Researchers at the Eurac Research institute in Bolzano identified four strains of yeast capable of surviving sub-zero temperatures in samples taken from the mummy's gut, skin, and melted tissue water.

Genetic testing showed the yeast DNA damage matched levels found in the original microbes, indicating the organisms entered the body shortly after death. The team reproduced the yeast in refrigerated conditions and attempted to ferment bread dough. " The same yeast strains demonstrated the ability to metabolize phenol, a chemical once used to preserve the remains, suggesting potential applications in breaking down similar contaminants in the environment.

Analysis of the mummy's gut bacteria also identified a microbial species now rare in industrialized populations but previously detected in certain traditional communities and in 3,000-year-old preserved feces from an Austrian salt mine. The study concluded the preserved body functions as an active biological system rather than a static specimen.

An independent researcher noted the yeast samples were collected in 2010 and 2019, limiting evidence that the organisms have persisted for thousands of years inside the remains.