Petrus was one of the first sour beers I’d ever tasted, and it certainly came as a shock. It was described as a “aged pale” and I paid more attention to the “pale” part of that phrase than the "aged." So when that sharp, biting bitterness and tongue-buckling sourness first hit me, it wasn’t quite a revelation; it was more like a bucket of cold water in the face. But two, three, four sips in, the flavors started to round out and emerge on my underdeveloped palate. There were oaky white wine notes, some underlying funkiness and hay qualities from the microflora in the aging process, minerals, herbs, and a bitter grapefruit and leathery finish. This was as complex a beer as I’d ever tasted. And this was the beginning of my curiosity in aged beers, specifically Belgian, and the next few years would provide no end to my tasting of these styles. More than a decade later, Yves Benoit and Albert de Brabandere are here in Chicago, visiting the Hopleaf which is where I had my first Petrus. They’re here on the heels of a major uptick in the number of sour beers being produced and consumed in the US. No, this will never be the new IPA, far from it, but for producers like Brouwerij de Branbandere, the makers of the Petrus line of sour blends, it’s a big opportunity to share one of Belgium’s greatest beers with a newly interested audience.