Proteomics Evidence Consistent with a Ginger-Flavored Alcoholic Beverage Found in the Corrosion of a 1500-1046 BCE...

During the Shang (ca. 1500-1046 BCE) and early Western Zhou (1046-978 BCE) periods in China, elite rituals involved offerings of food and drink presented to ancestors in elaborately cast bronze vessels. Although later texts describe these practices in detail, direct biomolecular evidence for vessel contents remains scarce. We analyzed corrosion from eight unprovenanced Chinese ritual bronzes at the Museum Rietberg (Zurich, Switzerland) using powder X-ray diffraction to characterize crystalline inorganic phases and nanoLC-MS/MS to target preserved proteins. Only one vessel (a hu-type) yielded diagnostic peptides preserved within a copper carbonate matrix, matched to proteins from ginger (Zingiber officinale) and a fermentation mold (Monascus purpureus). Serpin-domain-containing protein signals were also detected and are interpreted more cautiously. To our knowledge, this study provides the first direct proteomic evidence consistent with a fermented beverage residue associated with ancient Chinese recipes and supports the traditional interpretation of this vessel type in drink preparation and/or consumption. More importantly, we show that corroded, unprovenanced bronze vessels can preserve archeologically informative proteins, highlighting the value of proteomics for extending the scientific and curatorial significance of museum collections.