If you ever thought about going back in time and cracking open a cold one with the Egyptians, you might be surprised to find that ancient Egyptians drank a similar brewski to the ones on tap today.

The fermented drink featured prominently in Egyptian culture, a gift from the gods that graced pharaohs’ tombs and became the staple, everyday drink for men, women and children. To further probe the ancient Egyptian beer recipe, researchers recently took a physical sample from the vats of Egypt’s oldest brewery establishment (with a production volume reaching 650 bottles per vat!) and analyzed the chemical components of the preserved sludge.

Located in the Heirakonpolis archeological site near modern-day Edfu, archaeologists unearthed one of the oldest-known Egyptian breweries and earliest large-scale brewing site in the world in 2003, consisting of five free-standing ceramic vats. The vats had a thick, black film coating the interior. Early botanical analysis identified several components from the sludge, including emmer wheat, the staple ingredient of beer-making, and barley. However, the researchers analyzed the chemical composition further using instrumental methods, like gas chromatography-mass spectrometry and infrared spectroscopy, and discovered interesting additives.

Though we know a lot about ancient Egypt, this is the first time scientists have shown that ancient Egyptians (perhaps) purposefully added barley to their beer.

The researchers found that more than a quarter of the total sample consisted of phosphoric acid. Phosphoric acid is commonly used today as a drink preservative and flavor enhancer, originating from hops in modern-day beer. Interesting, the previously oldest-known usage of phosphoric acid in alcoholic fermentation was in Crete, dating to approx. 1700 BCE. These Egyptian samples pre-date those by about 2000 years (~3600 BCE).

Further analysis identified other volatile organic acids and esters found in modern-day beer (caprylic acid, capric acid, laurate, and geranyl acetone to name a few) and bourbon whiskey (γ-nonalactone, which creates a coconut-like smell). Amino acids additionally accounted for 27.4% of the sample, with proline consisting of the majority (25.3%) of the amino acids. Proline is enriched in fruits, and previous evidence showed the addition of dates and grapes in ancient Egyptian beer residues, though botanical analysis has not confirmed this.

Though we know a lot about ancient Egypt, this is the first time scientists have shown that ancient Egyptians (perhaps) purposefully added barley, because its fermentation and subsequent phosphoric acid release preserved the all-important beverage and prevented rapid spoilage.