科学美国人60秒:5600年前的埃及大桶用来酿造啤酒

This is Scientific American's 60-second Science, I'm Susanne Bard.
Some 5,600 years ago, people in the Egyptian city of Hierakonpolis did something that's still a very popular activity today: they brewed and drank beer. We know this because archaeologists examining the area near the ruins of a cemetery for the elite discovered a structure containing five ceramic vats that would have been heated from below. Residues in the vats confirmed that they had once made beer.
"And it's estimated that if these five vats were operating at the same time, 325 liters would have been produced, which is equal to 650 cans of Budweiser."
Texas Tech University microbiologist Moamen Elmassry. He says this ancient beer would have tasted very different from what our modern palates are used to. The Egyptian beer makers did use malted wheat and barley in the brewing process. But no one had mastered carbonation yet. So the resulting brew was a flat, unfiltered malt beverage with a low alcohol content.
Elmassry's colleagues recently sampled thick, dark deposits from the Hierakonpolis vats. The chemical analysis confirmed that they were indeed the product of beer making and not some other fermented food. The tests also revealed other ingredients ancient Egyptians put in their beer. The researchers found a high concentration of the amino acid proline, which is abundant in dates and some other fruits.
"This result suggests that dates could have been used or incorporated in the beer for flavor."
And maybe to add some sweet notes.

Hops—which act as both a flavoring and a preservative—weren't added to beer until medieval times.
"The use of hops was unknown to the ancient Egyptians, and we think that they used phosphoric acid to preserve their beer."
The residues were indeed high in phosphoric acid, a product of barley grains added during the fermentation process. Phosphoric acid is often used today to prolong the shelf life of alcoholic beverages.
Phosphoric acid via barley would have made it possible to mass-produce beer, store it for extended periods and even transport it—all consistent with the important role beer played in ancient Egyptian society. It not only provided hydration and nutrition but was also part of religious rituals among the elite.
The study is in the journal Scientific Reports.
studying ancient beer has allowed Elmassry to reflect on the intersection of science and history.
"I teach a microbiology lab, and we brew beer in the lab, and the students see the whole fermentation process. And thinking about how ancient Egyptians were able to do a similar thing thousands of years ago, it's kind of very special feeling."
Thanks for listening for Scientific American's 60-second Science. I'm Susanne Bard.