The earliest evidence of wine-producing could date back to 6000 BCE, as some wine residual compounds were found in ancient jars from Tbilisi, Georgia (read more here). However, due to the history of thousands of years, most ancient wines were not conserved well. Most of them are only left with a few residues such as amino acids that indicate evidence of alcoholic fermentation. These residues are usually found on pottery shards or in the soil near the container. Therefore, it is difficult to verify the complete composition of ancient wines by analyzing fermentation residues.
In October 2018, an ancient tomb was found in Shanxi province, China. This ancient tomb was assured to be built around 33 BCE in the late Han Dynasty. During excavation, a bronze jar was unearthed, in which a clear green liquid without odor was found. The liquid was then further analyzed using different methods such as gas chromatography and mass spectrometer. Monosaccharides, alditols, glycerol-related compounds, and organic acids were found in the liquid. Monosaccharides may be produced by the saccharification of fruits or grains, and the organic acids including lactic acid, pyruvic acid, oxalic acid, succinic acid, malic acid, tartaric acid, and citric acid are the result of alcoholic fermentation. Additionally, numerous sterols were also recovered from the liquids, indicating the existence of yeast cells. Combining these, this liquid is assured to be fermented liquor (the research paper can be found here).
Besides, ancient liquid wines were also found in other provinces in China, such as Shaanxi, Henan, Hebei, and Shandong. These wines were made from different ingredients, such as grape, black millet, rice, etc. Further analysis still needs to be carried out on these samples (read more here).
If you found an ancient wine, what do you want to analyze? Do you think you can figure out the fermentation methods used in the wine? Why was the wine in the bronze jar can be preserved well?
Image credit: National Museum of China