Good Things Come to Those Who Wait?
Ion chromatography helps students brew 5,000-year-old beer
Joanna Cummings |
Ever wondered how booze was made in ancient China? Well wonder no longer. A group of archeology students from Stanford University recently used some cunning chemistry to recreate Chinese beer using a 5,000-year-old recipe, giving them an insight into ancient culture and behavior.
But what drove the students to drink in the first place? After the excavation of the Mijiaya archeological site in northeast China, Li Liu (Sir Robert Ho Tung Professor in Chinese Archaeology) and postdoc candidate Jiajing Wang felt that the pottery assemblages from two pits – namely, the presence of funnels and stoves – could be related to alcohol making. In an attempt to prove this hypothesis, they visited Shaanxi Institute of Archaeology in Xi’an, where the artifacts were stored, and extracted residues for analysis from the interior surfaces of the vessels.
The team then used ion chromatography (IC) to analyze the residue. IC identified the presence of oxalate, which develops during the steeping, mashing, and fermentation of cereals. They also discovered traces of phytoliths from cereal husk, finding that the starch had damage consistent with being malted and mashed. In addition, the shapes and styles of the vessels showed stylistic similarities to brewing equipment of the historical period and modern ethnographic records. The conclusion? “People in China brewed cereal-based beer around 5,000 years ago – 1,000 years earlier than previously believed,” says Jiajing Wang.
From there it was a ‘hops’, skip and a jump for Liu’s students to replicate the ancient brew. The all-important taste tests revealed a sweeter, fruitier flavor than modern beers – though other variations apparently smelt more like “funky cheese”.
According to Wang, this kind of experiential archeology helps researchers make inferences about human behavior and Chinese culture at the time. “The practice of beer brewing is likely to have been associated with the increased social complexity in the Central Plain during the fourth millennium BC,” says Wang. “It indicates a mix of Chinese and Western traditions – barley from the West, millet, Job’s tears (a type of grass), tubers from China.” They were particularly surprised by the presence of barley, as the earliest prior evidence of barley seeds in China dates to 4,000 years ago. The authors suggest that it was initially introduced to the Central Plain as an ingredient for alcohol production rather than for subsistence.
The beer that students made and analyzed will be incorporated into the research team’s final findings. The team is planning to conduct more beer brewing experiments, so that they have more reference data to study ancient beer production. “This class gives students an opportunity to not only experience what the daily work of some archeologists looks like, but also contribute to our ongoing research,” Wang says. But since the beer has the consistency of porridge, it’s unlikely you’ll see it in a bar near you…
- J Wang et al., “Revealing a 5,000-y-old beer recipe in China”, PNAS, 113, 6444-6448 (2016)