Scientists Made Sourdough Bread With Yeast Found on Ötzi the Iceman’s Mummified Body

Discovered in the Alps in 1991, the remains are home to a wide variety of bacteria, fungi and yeasts

Sarah Kuta | Daily Correspondent

June 4, 2026 3:02 p.m.

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In 1991, hikers exploring the Tyrolean Alps between Italy and Austria discovered the mummified remains of a 5,300-year-old man. Since then, scientists have learned a lot about the mummy, nicknamed “Ötzi the Iceman,” including that he was going bald, had numerous tattoos and was infected with a cancer-causing strain of HPV.

Now, researchers say they have successfully made sourdough bread using yeast found on Ötzi’s body. Up next, they hope to try making beer.

“We want to pursue this further and involve specialized research teams from the food sector in the process,” Mohamed Sarhan, a microbiologist with the Institute for Mummy Studies at Eurac Research, says in a statement.

The findings suggest Ötzi is “not a static relic, but a dynamic biological system,” Frank Maixner, who directs the Institute for Mummy Studies, says in the statement. Sarhan and Maixner are co-authors of a new paper published June 3 in the journal Microbiome, which describes the community of microorganisms living on, in and around Ötzi’s body. 

Past studies had identified some of the microorganisms living in Ötzi's mouth and intestines. But researchers wanted to get a more comprehensive picture of the famous mummy’s microbiome, and they were curious to know whether any of the microbes were still active—and potentially damaging the remains.

Ötzi is housed at the South Tyrol Museum of Archaeology in Bolzano, Italy, in a special refrigerated chamber kept at 21 degrees Fahrenheit and 99 percent relative humidity. The conditions are meant to mimic the glacier that preserved Ötzi’s remains for centuries.

With permission from the museum’s leaders, Maixner and his colleagues defrosted the remains in April 2019. They kept Ötzi at 39 degrees Fahrenheit for five hours, until the layer of ice covering his entire body had melted.

They collected some of the ice chunks from the surface of his body, as well as the thawed water from both inside and outside the remains. They swabbed the outside of the body and collected samples from some of the exposed, internal areas of the remains. Additionally, they looked at soil samples collected from beneath the mummy during excavations in 1991 and samples taken from his body in 1992 and 2010.

Their analysis revealed a mix of ancient and modern microbes, including some that probably lived inside Ötzi while he was still alive and others that likely colonized his remains after he died. Others seem to have been introduced later during conservation work.

“We found that the spray ​water used to keep the mummy humid has introduced a dominant signature of bacteria onto his external surfaces,” Sarhan tells Reuters’ Will Dunham. “These modern introductions are effectively reshaping the mummy's external microbiome—a consequence of conservation practices that was previously unrecognized.”

One of the most surprising discoveries was the presence of four cold-adapted yeast strains derived from the glacier environment where the remains were buried.

The scientists found both ancient and modern DNA. And when they compared samples taken in 2010 and 2019, they saw that one strain, Glaciozyma, had proliferated to become the dominant strain. Together, the findings suggest the yeasts have remained metabolically active over the years, including under the current storage conditions.

“These yeasts have accompanied Ötzi on his long journey through the millennia,” Maixner says in the statement.

However, not everyone is convinced the yeast is active. To be sure, researchers would need to find RNA, which would show that the yeasts’ genes are switched on, Damla Kaptan, a paleogeneticist at the University of Stavanger who was not involved with the study, tells NewScientist’s Chris Simms. “There is still the possibility that the yeast remained dormant or became active to some extent during thawing,” she says.

Researchers didn’t find any evidence to suggest that the yeast and other microbes are harming Ötzi’s remains, per NewScientist. But they hope to conduct additional studies in the future to learn more about their effects on the body, reports Live Science’s Sophie Berdugo.

Ötzi is “the most important archaeological science finding of the 20th century and up until the present,” Patrick Hunt, an alpine archaeologist at Stanford University who was not involved with the research, tells Science News’ Tom Metcalfe. But preserving the remains is critical, he adds, so any discoveries related to “ongoing microbial contamination” are “vital to whatever interventions are needed.”

Scientists plan to continue studying Ötzi’s cold-loving yeast strains and experimenting to see whether they could have any practical applications, such as for the production of bread, beer or other fermented products.

“Yeasts that are active at very low temperatures can offer advantages in different areas,” Sarhan says in the statement. “If fermentation is possible at room temperature or even at refrigerator temperatures, energy can be saved since no additional heating is required. Furthermore, the yeasts could also be active during transport, meaning they could contribute to fermentation already on their way to the manufacturer.”

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Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.