Archaeologists have long known that ancient Egyptians made and drank wine, but the wine’s color has remained unconfirmed. A team of scientists recently developed a chemical technique that can identify whether the wine once contained in ancient jars was red.
Rosa Maria Lamuela-Raventós and her colleagues at the University of Barcelona collected residues from the interiors of five ancient-Egyptian pottery jars at the British Museum in London and the Egyptian Museum in Cairo. Another sample came from the tomb of King Tutankhamen, who reigned during the 14th century B.C.
To confirm that these jars at one time contained wine, the Spanish team analyzed the samples for trace amounts of tartaric acid, which is found almost exclusively in grapes. All but one of the samples tested positive. Then, to determine the color of the ancient wine, the researchers looked for evidence of malvidin-3-glucoside, a signature pigment in red wine.
The researchers didn’t look for the pigment itself because, over time, it binds with other chemicals to form a complex molecule that makes malvidin difficult to identify. However, the team found that chemically breaking down these complexes released syringic acid, which they then could readily detect using a combination of sensitive laboratory techniques. So far, the researchers have only looked at the King Tut jar residues, where they did find syringic acid. They describe their analysis in the March 15 Analytical Chemistry.
Patrick McGovern at the University of Pennsylvania Museum in Philadelphia says the method could also help researchers reconstruct a more accurate history of the domestication of grapes and winemaking.