May 22 (UPI) -- When researchers in Israel examined fragments of clay jars used to house beer and mead several thousand years ago, they discovered colonies of yeast hiding in the shards' nano-sized pores.
To help them extract the long-dormant yeast, scientists recruited the help of winemakers with experience aging wine in clay pots.
Archaeologists dated the clay fragments to several different historical periods, including the reign of Egyptian Pharaoh Narmer, who ruled Judea between 3100 and 3050 BC. Scientists also identified and extracted yeast from ceramic pieces dated to the reign of Aramean King Hazael, whose rule lasted from 842 to 800 BC. Several jugs dated to Judea's Persian rule during the 5th century BC were also used to isolate ancient beer yeast.
"We dug at Ramat Rachel, the largest Persian site in the Judaean kingdom, and found a large concentration of jugs," Yuval Gadot, an archaeologist at Tel Aviv University, said in a press rleease. "In a royal site like Ramat Rachel it makes sense that alcohol would be consumed at the home of the Persian governor."
Previous studies have shown there is a long history of beer making in the Near East.
In total, six strains of viable yeast were isolated from the pottery pieces and used to brew a handful of beer varieties.
"The greatest wonder here is that the yeast colonies survived within the vessel for thousands of years -- just waiting to be excavated and grown," said Hebrew University researcher Ronen Hazan. "This ancient yeast allowed us to create beer that lets us know what ancient Philistine and Egyptian beer tasted like."
Scientists have previously created beers inspired by the ingredients of ancient alcohol beverages, but researchers in Israel claim this is the first time ancient yeast have been used to brew ancient beers.
Because the researchers were able to isolate only a few yeast strains, it's hard to know how similar the beer they produced and drank was to the varieties consumed during ancient times. The beers brewed and consumed several thousands years ago were likely made using dozens of yeast varieties, produced by unique combinations of ancient grains.
Still, the feat of brewing 5,000-year-old beer is significant.
"Aside from the gimmick of drinking beer from the time of King Pharaoh, this research is extremely important to the field of experimental archaeology -- a field that seeks to reconstruct the past," Hazan said. "Our research offers new tools to examine ancient methods, and enables us to taste the flavors of the past."