Scientists Make Sourdough Bread Using Yeast Found in 5,300-Year-Old 'Ice Man' Ötzi

Scientists have discovered yeast in the body of "Ice Man" Ötzi that may have existed for thousands of years. They told Agence France-Presse that they have successfully made sourdough bread using the cultivated yeast.

"Ice Man" Ötzi died from an arrow to the back while walking in the Alps, which are now Austria and Italy, more than 5,300 years ago. The Egyptian pyramids had not yet been built when he died.

His body has since been covered by ice and mummified, only to be discovered in 1991 by two German hikers in South Tyrol, northern Italy.

To preserve the mummy, Ötzi has been kept at a constant temperature of minus 6 degrees Celsius (21 degrees Fahrenheit) since his discovery.

This has allowed the scientific team to conduct research carefully, offering a rare window into the lives of ancient humans.

According to the latest research published today in "Microbiome," a scientific team in Italy found that ancient and modern microorganisms within Ötzi's body are still active.

Mohamed Sarhan, the lead author of the study from Eurac Research in Bolzano, Italy, said: "We didn't expect to find yeast."

Thousands-Year-Old Yeast Can Make Bread and Detoxify Environmentally

The scientific team discovered four types of yeast in Ötzi's gut, skin, and the "slightly brown" fluid that leaked from his body upon thawing, all of which can survive below zero degrees.

These yeasts only survive in extremely cold environments like Antarctica, leading to the speculation that they entered his body at some point after his death.

Sarhan said that genetic analysis showed that the "DNA damage in Ötzi's gut was very close to the original microbiome," indicating that these yeasts entered his body shortly after his death.

"These yeasts have accompanied Ötzi through thousands of years of time," said study co-lead author Frank Maixner.

This group of scientists then replicated and cultured these gut yeasts in a refrigerator.

Sarhan said: "Every time we mention yeast, the first question people ask is: Can it be used to make bread?"

So, they followed public demand and attempted to make sourdough bread.

The microbiologist admitted that it was not smooth sailing at first, but after three months of effort, "we made very good sourdough bread."

When asked if they considered using this yeast to brew beer, he replied: "It's on the list."

The research report also mentioned more serious potential applications for this yeast in the future.

When Ötzi was found in 1991, he was initially treated as a regular corpse, and a chemical called phenol was used to prevent fungi from growing on the body.

However, this special yeast can decompose phenol, meaning it could be used in the future to break down this chemical in polluted environments.

Sarhan stated that it is currently unclear whether this yeast has caused any damage to Ötzi's mummy, and he called for continued observation and research.

Nikolay Oskolkov, a researcher at the Latvian Institute of Organic Synthesis who was not involved in the study, warned that the yeast samples were only collected in 2010 and 2019, which "provides limited evidence and makes it difficult to prove that these yeasts have reproduced in the mummy for thousands of years."