A mysterious sticky substance found in ancient bronze jars in southern Italy has finally been identified as honey, solving a 70-year-old archaeological puzzle. The discovery, detailed in a study published by the Journal of the American Chemical Society, sheds new light on the ritual and everyday uses of honey in classical antiquity.
The residue was originally excavated in 1954 from a Greek-era subterranean shrine in Paestum, roughly 60 kilometers south of Pompeii. At the time, eight bronze jars were found partially filled with a waxy, amber-colored substance that defied conclusive analysis for decades.
The latest investigation, led by chemists from the University of Oxford, used a battery of advanced chemical tests to determine the jars once held raw honey or honeycomb—a rare and fragile organic material to survive for more than two millennia.
Layers of Time, Sealed in Bronze
The shrine in Paestum, a key site of Magna Graecia, was likely built around the 6th century BCE and later repurposed for Roman rituals. Within it, archaeologists discovered not only the enigmatic jars but also ceremonial objects such as a wooden table and iron rods wrapped in wool, reinforcing the idea that these were ritual offerings, not domestic storage.
Back in the mid-20th century, early chemical tests on the jar contents produced inconclusive results. Researchers suggested the substance might be animal fat, perhaps contaminated with insect remains. But as analytical technology progressed, so too did the potential to revisit unsolved mysteries.
When the jars were loaned to the Ashmolean Museum in 2019 for exhibition, researchers saw an opportunity to re-analyze the residue using mass spectrometry, infrared spectroscopy, and other modern techniques.
These tools allowed scientists to map out the molecular breakdown of the material, identifying key markers consistent with glucose, fructose, and even royal jelly—a protein-rich secretion from worker bees used to nourish queen larvae.
A Complex Chemical Fingerprint
The real breakthrough, according to lead researcher Dr. Luciana da Costa Carvalho, came when the team discovered residual sugars and acids deep within the residue’s molecular structure. “The smoking gun for honey was finding sugars right in the heart of the residue,” Carvalho told New Scientist in an interview following the publication.
Alongside sugars, the team also detected peptides from a parasitic mite that preys on bee larvae—a clear indicator of hive-originated material. This layered biochemical profile helped distinguish between degradation products and original compounds, allowing researchers to reconstruct what the jars originally contained.
Over time, the cork seals that likely once protected the jars disintegrated, allowing oxygen and microbes to invade. This triggered a slow transformation of the honey, with microbial activity converting its sugars into acids, leaving behind the sticky, acidic residue that perplexed scientists for decades.
Sacred Sweetness and Ancient Science
Honey held significant symbolic and practical value in ancient Greek culture. Beyond its culinary uses, it was used in medicine, cosmetics, and particularly in rituals and sacrifices. Its preservation in the Paestum shrine aligns with historical accounts of honey being offered to gods and used in purification rites.
While identifying ancient food residues isn’t new, few studies have managed to preserve and identify sugars this old. According to Carvalho, the find illustrates how organic materials—normally the first to decay—can endure under specific conditions and still tell stories centuries later.
“These residues aren’t just traces of what people ate or offered to the gods,” Carvalho said in a statement from Oxford. “They are complex chemical ecosystems that reveal how substances changed over time, opening the door to future work on ancient microbial activity.”
The study echoes findings from similar biochemical research conducted in Egypt and Mesopotamia, where traces of ancient wine and oils have been identified in sealed amphorae. But honey, due to its natural antimicrobial properties and high sugar content, is particularly prone to slow fermentation and breakdown, making this discovery all the more remarkable.