Alcoholic beverages have long been known to fulfill an important socio-cultural function in ancient societies, including during ritual celebrations. A new study reveals evidence of beer drinking 9,000 years ago in southern China, which was likely part of a ritual to honor the dead. The findings are based on an analysis of ancient pots found at a burial site in Qiaotou, making the site one of the oldest in the world for early beer drinking. The results are reported in PLOS ONE.
The ancient pots were discovered in a platform mound (80 mx 50 m wide, with an elevation of 3 m above ground level), which was surrounded by an artificial ditch (10-15 m in wide and 1.5-2 m deep), based on ongoing excavations at Qiaotou. No residential structures were found at the site. The mound contained two human skeletons and several pottery pits with high quality pottery vessels, many of which were complete vessels. The pottery was painted with white slip and some vessels were decorated with abstract designs. As the study reports, these artifacts are likely among the “earliest known painted pottery in the world.” No such pottery has been found at other sites from this period.
The research team analyzed different types of pottery found at Qiaotou, which were of different sizes. Some of the pottery vessels were relatively small and similar in size to drinking vessels used today and those found in other parts of the world. Each of the jars could essentially be held in one hand like a cup unlike the storage containers, which are much larger. Seven of the 20 ships, which were part of their analysis, appeared to be long-necked Hu pots, which were used for drinking alcohol in later historical periods.
To confirm that the vessels were used to drink alcohol, the research team analyzed residues of microfossils – starch, phytoliths (fossilized plant residues) and fungi – extracted from the interior surfaces of the jars. The residues were compared to control samples obtained from the soil surrounding the containers.
The team identified microbotanical (starch granules and phytoliths) and microbial (molds and yeasts) residues in the jars that matched residues from beer fermentation and are not found naturally in soil or other artifacts unless they contained alcohol.
“Through an analysis of pot residues from Qiaotou, our results revealed that the pottery vessels were used to hold beer, in its most general sense – a fermented drink made from rice (Oryza sp.), a grain called Job’s tears (Coix lacrima-jobi), and unidentified tubers,” says co-author Jiajing Wang, assistant professor of anthropology at Dartmouth. “This ancient beer, however, would not have been like the IPA we have today. Instead, it was probably a slightly fermented, sweet drink, which was probably cloudy in color.”
The results also showed that phytoliths from rice husks and other plants were also present in the pot residues. They may have been added to beer as a fermentation agent.
Although the Yangtze River Valley in southern China is known today as the country’s rice heartland, the domestication of rice occurred gradually between 10,000 and 6,000 years ago. At 9,000 years ago, rice was still at an early stage of domestication. At that time, most communities were hunter-gatherers who relied primarily on foraging. As the researchers explain in the study, since harvesting and processing rice was labor intensive, Qiaotou beer was likely a drink/beverage of ritual significance.
Analysis of the jar residue also showed traces of mold, which was used in the beer-making process. The mold found in the Qiaotou pots was very similar to the mold found in koji, which is used to make sake and other fermented rice drinks in East Asia. The findings predate earlier research, which found that mold was used in fermentation processes 8,000 years ago in China.
Beer is technically any fermented beverage made from cultures through a two-step transformation process. In the first phase, enzymes transform starch into sugar (saccharification). In the second phase, the yeasts convert the sugar into alcohol and other states like carbon dioxide (fermentation). As the researchers explain in the study, mold acts much like an agent for both processes, serving as a saccharification-fermentation trigger.
“We don’t know how people made the mold 9,000 years ago, because fermentation can occur naturally,” says Wang. “If people had leftover rice and the grains were moldy, they might have noticed that the grains became more sweet and alcoholic with age. Although people might not know the biochemistry associated with moldy grains , they probably observed the fermentation process and put it to use by trial and error.”
Since the Qiaotou pottery was found near burials in a non-residential area, researchers conclude that the beer pots were likely used in ritual ceremonies related to the burial of the dead. They speculate that ritualized consumption may have been integral to the establishment of social relationships and cooperation, which served as a precursor to the complex rice-growing societies that emerged 4,000 years later.