Iron Age salt miners ate blue cheese and beer

Fungi found in ancient feces recovered from the Hallstatt salt mines in Austria are the earliest evidence of people eating blue cheese and drinking beer in Iron Age Europe.

The salt mountains of Hallstatt in the Eastern Alps have been mined since at least the 14th century B.C. and mining has been continuous ever since. Excavations have unearthed multiple layers dense with evidence of mining activity during the early Iron Age (800-400 B.C.). Objects include wooden tools, fur, hide, wool and textile fragments, ropes and beautifully preserved human feces. These paleofeces, rapidly desiccated in the dry, perpetually cool and salty air of the underground mines, can be radiocarbon dated and analyzed to discover what people ate, what parasites they had, details about the microflora and fauna of their digestive system.

This study looked at three samples of paleofeces from the Bronze Age and Iron Age layers of the Hallstatt mine, and one sample from the 18th century. Even though the samples had been excavated as far as back as 1983, researchers were able to retrieve DNA and proteins that were almost entirely undamaged thanks to the rapid desiccation of the paleofeces in the salt mine environment.

Analyses found that all four samples came from four individual males. Researchers tested for 15 of the most abundant species found in the guts of modern-day populations. They found 13 of them, 11 of them more prevalent in non-Westernized populations. Microscopic analysis of the dietary components found that the Bronze Age sample was heavy on cereals — barley, spelt, emmer, millet. The Iron Age samples were also cereal-rich, with beans, opium poppy seeds, crab apples, cranberries rounding out the diet. Molecular analysis of DNA and protein biomolecules confirmed the presence of the cereals, seeds and fruit varieties and also revealed the presence of walnuts. The plants were supplemented by beef and pork.

It was one of the Iron Age samples that contained the biggest surprise: a high abundance of DNA and proteins from Penicillium roqueforti and Saccharomyces cerevisiae fungi. The research team confirmed these were not contaminants but are indeed of ancient origin, and were used in deliberate fermentation to produce a non-Roquefort blue cheese and beer. Had the fermentation been spontaneous, there would have been yeast species present in the paleofeces that are not there. Wooden cradles have also been unearthed in the mines that are believed to have been used as cheese strainers.

“The Hallstatt miners seem to have intentionally applied food fermentation technologies with microorganisms which are still nowadays used in the food industry,” [the Eurac Research Institute for Mummy Studies’ Frank] Maixner says.

The findings offer the first evidence that people were already producing blue cheese in Iron Age Europe nearly 2,700 years ago, he adds.

The study has been published in the journal Current Biology and can be read in its entirety here.