Characterization of liquor remains in Beibaie site, central China during the 8th century BCE

[Display omitted] •A comprehensive analysis process to characterize the ancient liquor residues, including liquid remains.•Syringic acid is more suitable as a marker of fruit wine, not necessarily wine.•The earliest fruit wine (2700-year-old) in East Asia, which may have been filtered. The analysis of solid residues and absorbed residues from archaeological contexts have developed rapidly, while the study of liquid residues is rarely reported. Liquid residues are often linked to liquor (alcohol beverage) in China, but most of them have not been scientifically confirmed. Liquor has a nonnegligible influence on the history of human society, so it is important to characterize the liquor residue from the archaeological context. Moreover, it is generally believed that grain liquor has been mainly produced in East Asia for a long time, but grape wine did not appear until the Han Dynasty (202 BCE- CE 220). In this study, a comprehensive analysis process of liquor residues with GC–MS and HPLC-MS/MS was designed and applied to liquid and silts unearthed at the Beibaie Cemetery (around 8th century BCE) in central China. The presence of volatile organic matters, organic acids, alcohols, esters and sugars shows that these samples should be liquor remains. Then, this study discussed the limitations of organic acid criteria to judge the liquor type and emphasized the indicative significance of syringic acid to identify fruit wine. Thus, the general detection of syringic acid in the residues from Beibaie Cemetery indicates that they are the earliest known fruit wine remains in East Asia up to now, which advances the history of China’s fruit wine-making by at least 500 years.