Scientists Found Sticky Goo Inside a 2,500-Year-Old Jar. Seventy Years Later, They Finally Know What It Is

By studying the mysterious substance’s chemical makeup, scientists determined the pot was once full of honey

Sarah Kuta | Daily Correspondent

August 1, 2025

Bronze jar next to sticky substance in scientific container — In the 1950s, archaeologists found bronze jars in an underground shrine (left). They contained a mysterious sticky residue (right). University of Oxford

In 1954, archaeologists discovered a 2,500-year-old underground shrine in southern Italy. Inside, they found eight bronze pots filled with a mysterious, orangeish-brown sticky residue.

Now, they finally know what was stored inside the jars all those years ago: honey, likely in the form of honeycomb.

Researchers used a variety of modern techniques to analyze the contents, with the results all pointing toward the sweet, golden-colored liquid produced by bees. They reported their findings July 30 in the Journal of the American Chemical Society.

The shrine is located in the ancient city of Paestum, roughly 40 miles south of Pompeii. Between the 1950s and 1980s, several teams of researchers conducted various experiments on the contents of one of the jars. They initially suspected the pots contained honey, but their testing suggested otherwise. They eventually concluded the jars held animal or vegetable fat that had become contaminated by pollen and insect parts.

More recently, when the jar came to the University of Oxford’s Ashmolean Museum for a 2019 exhibition, scientists decided to reinvestigate the goo. They used multiple different methods to understand the substance’s chemical makeup, then compared those results to samples of modern honey and honeycomb from Greece and Italy.

“The application of multiple analytical techniques was key to the success of this study,” says co-author James McCullagh, a chemist at the University of Oxford, in a statement. “By applying several mass spectrometry and spectroscopic approaches, we were able to reveal a comprehensive picture of the residue’s molecular composition—enabling us to distinguish between contaminants, degradation products and original biomarkers.”

Honey identified in offering in 2,500-year old Greek shrine

Their experiments revealed that the residue contained a mix of acids and degraded sugars. The scientists detected glucose and fructose, which are the primary sugars found in honey.

“The smoking gun for honey was finding sugars right in the heart of the residue,” says lead author Luciana da Costa Carvalho, also a chemist at the University of Oxford, to NewScientist’s James Woodford.

Testing also revealed the presence of royal jelly, a milky protein secreted by honeybees, as well as peptides from the relative of a parasitic mite that feeds on honeybees' larvae.

Based on what they now know, scientists suspect the jars were initially topped with cork seals. But, over time, those seals disintegrated, which allowed microbes and oxygen to infiltrate the jugs. Eventually, the bacteria ate most of the sugar, leaving only an acidic, waxy substance for researchers to find centuries later.

The residue probably tastes like “washed honeycomb but slightly more acidic," Carvalho tells LiveScience’s Kristina Killgrove, though she has not tasted it herself.

Ancient Greeks thought of honey as a “superfood,” using it in everything from food and medicine to cosmetics and rituals, Carvalho says in a university video. Researchers suspect the honey found in the shrine at Paestrum—which also contained a wooden table and iron rods wrapped in wool—was an offering to a deity.

But ancient residues are more than just “traces of what people ate or offered to the gods,” says Carvalho in a statement.

They are also “complex chemical ecosystems,” she adds. “Studying them reveals how those substances changed over time, opening the door to future work on ancient microbial activity and its possible applications.”

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