The Bones and the Ergot: The 2020 Discovery

“In 2019-2020, archaeologists found ergot alkaloids in dental calculus at an Eleusinian cult site in Catalonia. The hypothesis that had been argued from text for forty years found its first physical evidence.”

The Road to Eleusis was published in 1978. For forty years, it argued from text: the classical testimonies, the Homeric Hymn to Demeter, the pharmacological analysis, the architectural argument about the Telesterion. Compelling and unconfirmed.

In 2019-2020, Juan-Tresserras's bioarchaeological analysis of material from Mas Castellar de Pontós, an ancient Catalan site associated with the Demeter cult, produced significant findings. In dental calculus from a woman buried at the site in the third to second century BCE, apparent ergot alkaloids were identified. In a sealed ritual vessel, ergot spores and residues were found in association with beer-making equipment.

The Catalonia site is not Eleusis. It is an Eleusinian-affiliated sanctuary in the western Mediterranean. But it demonstrates that the cult of Demeter used grain-based preparations that incorporated ergot.

The 2026 Scientific Reports paper by Antonopoulos and colleagues then demonstrated experimentally that the preparation method available in antiquity, using lye from wood ash, converts toxic ergot alkaloids into water-soluble psychoactive forms. The chemical pathway was feasible. The archaeological evidence of its use exists at an Eleusinian site.

The hypothesis has gone from 'this might be possible' to 'this was demonstrated to be chemically feasible and archaeologically evidenced at a cult site.' The remaining question is whether the evidence will be found at Eleusis itself.

Sources

• Mas Castellar de Pontós excavation reports (2019-2020) [Source not found; under review]
• Antonopoulos et al., Scientific Reports (2026)