Here’s what you’ll learn when you read this story:

• A fourth-century B.C.E. Chinese tomb revealed a bronze bottle filled with a preserved alcoholic beverage.
• The 2,300-year-old bottle contained cereal grains, and displayed masterful fermentation techniques.
• The bottle’s garlic-head shape was commonly used to hold alcohol in Qin culture.

If you think you like your alcohol aged to perfection, a recent discovery in China has a response: Hold my beer.

Excavations inside Tomb M39 at the Shanjiabo cemetery—roughly a mile from the Qin Great Wall—revealed a bronze bottle containing a hefty 15 cups of 2,300-year-old beer, incredibly well sealed and preserved within the tomb.

In a study published in the Journal of Archaeological Science: Reports, a team investigated the contents of the bottled alcoholic beverage, which is dated between 547 and 221 B.C.E. The researchers’ goal was to better understand how beer brewing was practiced during the time of the Qin state.

“This study provides archaeological evidence of the Qin people’s beer-making practices,” the authors wrote, “directly reflecting authentic brewing technology, diverse cereal use, and even the good sealing method.” The new research adds another recipe to the extensive history of traditional Chinese brewing techniques.

Analysis of the odorless, pale, blue-green liquid revealed that it contains more than 2,400 unique chemical compounds. The results confirmed that this liquid wasn’t formed by accident. “The large number of compounds, far exceeding that in the control soil sample, indicated that the liquid preserved in vessel M39:5 was not simply infiltrated groundwater, but an authentic ancient organic residue,” the authors wrote. “The liquid was likely an alcoholic beverage.”

And a complicated one, at that. The results indicate that the liquid was a cereal-based beverage—think beer—with high concentrations of lactic acid and oxalic acid, and low concentrations of tartaric acid. With 23 other classes of organic compounds (ranging from amino and fatty acids to carbohydrates) the intricate sugars found in the liquid reveal that its makers had a deep understanding of fermentation.

Before even analyzing the contents, the researchers had a definite hint that the bottle contained an alcoholic beverage. The bronze container featured a mouth shaped like a head of garlic, which was a common stylistic motif in ancient Chinese culture for bottles holding alcoholic beverages.

The Qin beer featured 8,571 yeast cells, proso millet, wheat, barley, and amino acids that were added for flavorin, showing off a refined and technical brewing process executed by Qin beer makers.

“The discovery of thousands of yeast cells in the ancient Shanjiabao cereal-based alcoholic beverage may indicate the superior performance of the starter used by the Qin people,” the authors wrote. “The liquid was a cereal-based alcoholic beverage and not fruit wine.”

The combination of broomcorn millet and wheat or barley with a fermentation starter represents a unique brewing technique from the Qin people that hasn’t been found elsewhere in historical writings so far.

To make the liquid last, the brewers followed a well-known local practice of sealing the inside of the uncapped bottle with fabric and mixing mud and organic compounds over the top. Interestingly, this type of double-layer sealing technique was also commonly used in ancient Chinese cemeteries.

The Shanjiabo cemetery, featuring 183 tombs, was likely a publicly accessible resting place for both local troops and civilians. The healthy amount of beer properly sealed within an otherwise normal tomb suggests that Qin brewers had mastered the advanced art of fermentation starter techniques and flavor profiling, making it accessible to many. Now, if we could just mimic that recipe…