Alpine archaeology yields 5,300-year-old yeast for modern bread

More than five thousand three hundred years ago, a man died in the high Alps on the border between what is now Austria and Italy. His body, preserved by ice and altitude, lay undisturbed until 1991, when hikers found him near the Similaun glacier. Scientists have now extracted yeast from his gastrointestinal tract and used it to produce sourdough bread, according to reporting by CBS News and the international scientific community.

The yeast, which has survived millennia in the frozen mummy's gut, represents a living link to Alpine subsistence practices of the Neolithic period. Researchers identified the microorganism and cultivated it in laboratory conditions, then employed it in a traditional fermentation process. The resulting bread offers a tangible connection to the dietary habits of mountain communities five thousand years before the Roman conquest of the Alps.

The discovery underscores the role of fermentation in early Alpine food culture. Sourdough fermentation, which requires wild yeast and bacterial cultures, would have been essential to preserving grain harvests through long mountain winters. That a single organism survived so long in frozen tissue suggests the extreme conditions of high-altitude preservation—the very conditions that define the Valle d'Aosta's climate and ecology today.