Using bizarre or unconventional ingredients in beer has been the norm since the craft beer boom started—anything to set your brewery apart from the others and get some press. Whether it’s carrots or donuts or beard yeast, everyone is trying to up the ante and delve into uncharted waters. The Roskilde music festival in Denmark—northern Europe’s largest such festival—is taking this one step further with an ingredient no one would ever think to put in beer: urine.

The festival, which has noticed the concert-goers pee has had quite the negative effect on the local sewage system and environment, is harvesting the waste to fertilize local fields of barley which will eventually be turned into beer. Clearly, the urine usage could be much worse and will (fortunately) not be making it directly into the beer. And the “beercycling” gave festival-goers the ability to personally contribute to the new beer—many times over, probably—which could be available at the festival as early as 2017. And just think—you’ll also get to imbibe contributions from the likes of Paul McCartney and Pharrell Williams!