Winemaking practices in coastal Italy during the Roman period involved using native grapes for making wine in jars waterproofed with imported tar pitch, according to a study published in the open-access journal PLOS ONE by Louise Chassouant of Avignon University and colleagues.

From the amphorae to understanding the content; this multi-analytical analysis relied on  archaeobotany and molecular identification [Credit: Louise Chassouant]

The authors examined three Roman period amphorae -- wine jars -- from a seabed deposit near the modern harbour of San Felice Circeo, Italy, about 90 km southeast of Rome. A combination of chemical markers, plant tissue residue, and pollen provided evidence of grape derivatives and pine within the jars. 

The evidence suggests the amphorae were used in both red and white winemaking processes, while the pine was used to create tar for waterproofing the jars and perhaps also flavouring the wine, as has been observed at similar archaeological sites.

Microscopic observation of (A) archaeological plant tissues trapped in the resin of SFC1; (B) filament  from the stamen of a modern wild Vitis vinifera flower, and (C) ESEM observation of a transverse  section of charred Pinus wood trapped in the SFC2 pitch. The white arrow indicates the resin canal [Credit: Louise Chassouant et al, 2022]

The grapevine pollen matches wild species from the area, suggesting these winemakers were using local plants, although it remains unclear whether these were domesticated at the time. The pine tar, on the other hand, is non-local, and was likely imported from Calabria or Sicily based on other historical sources.

The authors emphasize the benefit of this multidisciplinary approach to characterize cultural practices from archaeological artefacts. In this case, the identification of plant remains, chemical analysis, historical and archaeological records, amphorae design, and previous findings all contributed to the conclusions of this analysis, providing an example of methodology for interpreting a history beyond the artefacts which would not be possible using a single technique.

Vitis pollen in polar and equatorial view. Pollen grains recovered from: A, B. Fossil sediments from  Rignano Flaminio (18–22 μm); C, D. Surface of modern wild fruits of Vitis from Tivoli (20–24 μm); E, F. Pitch of amphora SFC1; G, H. Pitch of amphora SFC5; I, J. Pitch of amphora SFC2 [Credit: Louise Chassouant et al, 2022]

The authors add: "If there was a message to be retained from the reading of this article, it would be related to the multidisciplinary methodology to be applied. Indeed, 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."

Source: Public Library of Science [June 29, 2022]