Ancient Romans seem to have used local grapes and out-sourced tar pitches while making wine, a new study reveals.
A group of researchers from Italy and France has analyzed three different wine jars, or amphorae, discovered off the coast near the San Felice Circeo harbor in Italy, dating back to 1 to 2 BCE.
The findings were not limited to wine jars but included other ceramics and artifacts, making the archaeologists think that area was probably close to a Roman canal.
The study was published in PLOS One.
Making wine in ancient Rome
Researchers combined the latest chemical analysis techniques with various approaches in archaeobotany to bring more to light, which wouldn't be possible with traditional analysis techniques, Science Alert reported.
In order to identify and sort out chemical markers in jars, researchers tapped into gas chromatography and mass spectrometry and worked on the organic residue left in the ancient findings. The team discovered evidence of pollen and plant tissues of Vitis flowers, which led the scientists to think that jars were used to make red and white wine based on local sources.
Pine was also among the findings inside the jars, and it is thought to be used as the tar source to waterproof the jars, and add flavor to the wine. However, pine could have been sourced from other regions such as Calabria or Sicily.
"By using different approaches to unravel the content and nature of the coating layer of Roman amphorae, we have pushed the conclusion further in the understanding of ancient practices than it would have been with a single approach," researchers said.
Pine tar as a water-proof agent
This is not the first time ancient Romans pioneered a specific process that still maintains applications today in the modern world. Having used pine tar as a water-proof agent, it is evident that Romans mastered the process's chemistry back then to preserve wine in amphorae even centuries ago.
Today, mariners commonly use pine tar as a wood preservative, wood sealant to protect the integrity of the piece in question with water-proof properties.
We hereby investigate the pitch used for coating three Roman amphorae from San Felice Circeo (Italy) through a multidisciplinary study. The identification of molecular biomarkers by gas chromatography—mass spectrometry is combined with archaeobotanical evidence of pollen and plant tissues of Vitis flowers. Diterpenic chemical markers together with Pinus pollen and wood revealed Pinaceae tar coating. Aporate 3-zonocolpate pollen, identified as Vitis, together with tartaric, malic and pyruvic acids elucidate the grape-fermented nature of the content. Our conclusions open new consideration on the use of grape derivatives that cannot be supported by traditional analytical methods. Based on the finds of aporate Vitis pollen, found also in local modern and Middle Pleistocene samples, we hypothesize the use of autochthonous vines. The presence of a medicinal wine (historically reported as oenanthium) is also considered. We interrogate Vitis pollen capacity to target grapevine domestication, thereby providing innovative tools to understand such an important process. We anticipate our study to encourage a more systematic multidisciplinary approach regarding the analyses of wine amphorae.