A caccabus (a wide-mouthed copper alloy vessel used for cooking) was amongst the objects lent by the Parco Archeologico di Pompeii and exhibited at the Ashmolean Museum in Oxford (UK) in 2019. Kept in storage since excavation in the 1950′s, the object’s preparation for display presented an opportunity to investigate organic residues that may be trapped in its corrosion - a material currently commonly removed by conservators during the cleaning process. We adopted a multi-analytical approach to corrosion characterization comprised of Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and mass spectrometry techniques, including proteomics. Within the copper hydroxide carbonate matrices were markers for milk, beef and the fermentation of cereals, supporting the proposed use of the vessel in the past. The practice of removing corrosion from objects for display is widespread, leading to a significant level of information about life and culture being lost. Our research not only extends organic residue analysis in archaeology but has the potential to change current conservation practice.
