A book of 12th-century beer recipes is being used to recreate beers from the past. The books were discovered in the archives at Grimbergen Abbey, a monastery founded in Grimbergen, Belgium in 1128.

The books, which Grimbergen Abbey has had possession of for some time, once belonged to the Norbertine monastery, which was burned down by French revolutionaries in 1798, the Guardian reports.

Now, after four years of research, the 220-year-old recipes are being resurrected. The brew will yield a hefty Belgian ale of 10.8 percent ABV. The ale is being produced by Carlsberg, based in Copenhagen, Denmark, which currently produces Grimbergen-brand beer for markets outside of Belgium; and by Alken-Maes brewery for the Belgian market.

“We had the books with the old recipes, but nobody could read them,” Father Karel Stautemas, the abbey’s subprior, said. The recipes were written in old Latin and old Dutch, so the abbey brought in volunteers to study the texts.

“We’ve spent hours leafing through the books and have discovered ingredient lists for beers brewed in previous centuries, the hops used, the types of barrels and bottles, and even a list of the actual beers produced centuries ago,” he said.

An interesting aspect of the recipes is their use of hops, which was novel at the time, when monasteries brewed with other herbs. That said, the beer recipe will be tweaked to cater to modern tastes.