While there are some truly outrageous craft brews out there — which incorporate everything from frozen pizza to squid ink — Utah homebrewer Dylan McDonnell took on the ultimate beer experiment when he set out to replicate an ancient Egyptian recipe with real ancient yeast.

McDonnell, who also holds a master’s degree in Middle Eastern studies, was inspired by the creative at-home baking that took place during the pandemic. He recalls seeing video game designer Seamus Blackley sharing on social media about baking bread with 4,500-year-old Egyptian yeast. As an ambitious homebrewer, McDonnell wondered if he could replicate the concept with beer.

The process would end up taking over three years, as McDonnell carried out meticulous research to create what would be the “closest approximation yet to what Rameses the Great may have been drinking between battles with the Hittites,” according to The New York Times. First, McDonnell studied the Ebers Papyrus, an ancient Egyptian medical text that contains recipes from 1500 B.C.E. Out of the 75 beer recipes, he decided to use the eight most frequently mentioned ingredients, which included desert dates, Yemeni Sidr honey, sycamore figs, Israeli golden raisins, prickly juniper berries, carob fruit, black cumin, and frankincense — a combination that would still be considered pretty out-of-the-box in today’s world of crazy craft brews. He selected purple Egyptian barley and emmer wheat as the base grains. Tracking down the ingredients proved difficult, but McDonnell encountered some luck along the way. One friend who happens to be an architectural historian helped him source the most difficult to find, the sycamore figs.

As for tracking down the ancient yeast strain, McDonnell sought out German company Primer’s Yeast, which extracts and stores ancient yeasts. He selected a batch that had been taken from an amphora found in Israel that had most likely been used for brewing around 850 B.C.E.

“It was by far the most important part of the process,” he told The New York Times. “To me, this would have just been another fun beer I made that isn’t noteworthy if it didn’t include the yeast.”

The result was a 5-percent ABV beer that he says is similar to a gose, a tart German style. McDonnell named the brew the Sinai Sour, referring to the Sinai Peninsula in Egypt. He has no plans to sell the beer, but is open to hosting private tastings.