Prehistoric wine discovered in inaccessible caves forces a rethink of ancient Sicilian culture

Monte Kronio rises 1,300 feet above the geothermally active landscape of southwestern Sicily. Hidden in its bowels is a labyrinthine system of caves, filled with hot sulfuric vapors. At lower levels, these caves average 99 degrees Fahrenheit and 100 percent humidity. Human sweat cannot evaporate and heat stroke can result in less than 20 minutes of exposure to these underground conditions.

Nonetheless, people have been visiting the caves of Monte Kronio since as far back as 8,000 years ago. They’ve left behind vessels from the Copper Age (early sixth to early third millennium B.C.) as well as various sizes of ceramic storage jars, jugs and basins. In the deepest cavities of the mountain these artifacts sometimes lie with human skeletons.

Archaeologists debate what unknown religious practices these artifacts might be evidence of. Did worshipers sacrifice their lives bringing offerings to placate a mysterious deity who puffed gasses inside Monte Kronio? Or did these people bury high-ranking individuals in that special place, close to what was probably considered a source of magical power?

One of the most puzzling of questions around this prehistoric site has been what those vessels contained. What substance was so precious it might mollify a deity or properly accompany dead chiefs and warriors on their trip to the underworld?

Using tiny samples, scraped from these ancient artifacts, my recent analysis came up with a surprising answer: wine. And that discovery has big implications for the story archaeologists tell about the people who lived in this time and place.

Analyzing scraping samples

The storage jars and their mysterious contents, left millennia ago in the recesses of Monte Kronio. Davide Tanasi et al. 2017, CC BY-ND
In November 2012, a team of expert geographers and speleologists ventured once again into the dangerous underground complex of Monte Kronio. They escorted archaeologists from the Superintendence of Agrigento down more than 300 feet to document artifacts and to take samples. The scientists scraped the inner walls of five ceramic vessels, removing about 100 mg (0.0035 ounces) of powder from each.

I led an international team of scholars, which hoped analyzing this dark brown residue could shed some light on what these Copper Age containers from Monte Kronio originally carried. Our plan was to use cutting-edge chemical techniques to characterize the organic residue.

We decided to use three different approaches. Nuclear magnetic resonance spectroscopy (NMR) would be able to tell us the physical and chemical properties of the atoms and molecules present. We turned to scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) and the attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR) for the elemental analysis – the chemical characterization of the samples.

There were no second chances with the tiny amount of samples that had been scraped from the ancient vessels. Davide Tanasi, CC BY-ND
These analysis methods are destructive: The sample gets used up when we run the tests. Since we had just that precious 100 mg of powder from each vessel, we needed to be extremely careful as we prepared the samples. If we messed up the analysis, we couldn’t just run it all over again.

We found that four of the five Copper Age large storage jars contained an organic residue. Two contained animal fats and another held plant residues, thanks to what we inferred was a semi-liquid kind of stew partially absorbed by the walls of the jars. But the fourth jar held the greatest surprise: pure grape wine from 5,000 years ago.