A Sticky Goo Was Found Inside 2,500-Year-Old Jars — Scientists Finally Realized What It Was

About 50 miles south of Naples, tucked in a shadowy understorey of what is now a temple, eight fat-bottomed bronze jugs had been sitting since the 6th century BC. The jars were filled with a sweet substance and topped with cork seals, but at one point in time, the humid conditions of the underground prompted the seals to loosen up. Gradually, armies of ancient microbes lurking around spilled out of the jars and ate up all the sugars trapped in the sweet material. In 1954, some researchers exploring the location stumbled upon these jars and found this sweet, viscous liquid oozing within. What this liquid was, remained unclear.

Fast forward to 2025, scientists have, at last, figured out the true identity of this substance, as they documented in the Journal of the American Chemical Society. Discovered in the Paestum shrine of Southern Italy, the jars are believed to be 2,500 years old, each one filled with mysterious, orange-brown sticky residue that resembles a waxy substance. Only recently, researchers concluded that the substance is nothing other than “honey,” or what they called “a symbol of immortality.” Describing the taste of it to Live Science, lead author Luciana da Costa Carvalho said it tastes like “washed honeycomb but slightly more acidic."

Costa Carvalho, who is also a chemist at the University of Oxford, revealed in a video that this honey was once considered a superfood by the Greeks, likely serving as a worship ritual to the gods. Today, the honey might not be as fit to be served to the gods as it was then. But it is no less valuable either, especially when it comes to science. Recognizing these jugs and the honey scurrying inside them as prized vaults of biological intelligence, they examined them in detail using techniques like mass spectrometry and chromatography.

While mass spectrometry told them the composition of its molecules and compounds, chromatography provided them with a chemical fingerprint they could utilize to study ancient honey. The tests 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 honeybee larvae. Accompanying the bronze jars were also two amphorae surrounding an empty iron bed. The researchers suspected that the jars containing animal or vegetable fat had become contaminated by pollen and insect parts. But recently, when the jar was brought to the University of Oxford’s Ashmolean Museum for a 2019 exhibition, they decided to re-investigate its chemical makeup.

“Our multianalytical approach detected lipids, saccharide decomposition products, hexose sugars, and major royal jelly proteins supporting the hypothesis that the jars once also contained honey/honeycombs,” they noted in the paper. Study co-author James McCullagh, a chemist at the University of Oxford, shared that the success of the study was attributed to their use of multiple analytical techniques, which allowed them to paint a comprehensive picture of both the honey and the jugs. “The research highlights the value of reinvestigating archeological residues in museums with advanced biomolecular techniques and offers a more specific method for detecting bee products in ancient contexts,” concluded the researchers.