ZU, also known as Zubrowka, is a Polish bison-grass vodka that’s been around for centuries. Bison grass? Like the name suggests, it’s a favored food of bison, which still roam freely in a particular remote Polish forest. It’s there that Zubrowka harvests the grass that flavors its vodka. The vodka itself is made from rye, distilled four times so it’s particularly smooth, and infused with that distinctive bison grass.