In order to identify accurately the circular object contained in the ceramic pot excavated from Jurou Li's grave of the Jin dynasty (1115–1234 ce) in Xi'an, Shaanxi, China, mass spectrometry was applied to determine the amino acid sequences of the residual proteins extracted from the sample, after preliminary starch grain analysis. The sequences were searched against a standard protein sequence database. The proteins extracted were identified as originating from domesticated barley (Hordeum vulgare), soybean (Glycine max), and fermentative microorganisms (Kluyveromyces lactis, Lipomyces starkeyi, Wickerhamomyces ciferrii, Nadsonia fulvescens and Zygosaccharomyces rouxii). These findings indicate that the extremely degraded object in the ceramic pot was made from barley by fermentation with the addition of soy sauce, providing direct evidence of culinary culture in the Jin dynasty.

In order to accurately identify the ancient liquid contained in the plum vase excavated from Jurou Li's Grave of the Jin Dynasty (1115-1234 CE) in Xi'an, mass spectrometry was applied to determine the amino acid sequences of the residual proteins extracted from the liquid sample. The sequences were searched against a standard protein sequence database. The proteins extracted was identified as glycosyltransferase from Sorghum bicolor, calcium-dependent protein kinase 2 from Wickerhamomyces ciferrii, and cytochrome b-c1 complex subunit Rieske from Nadsonia fulvescens. These findings indicate that the extremely degraded liquid in the plum vase was made from the cereal of sorghum by alcoholic fermentation of Wickerhamomyces ciferrii and Nadsonia fulvescens, providing direct evidence for liquor in the Jin Dynasty.