In a world full of stainless steel, just a handful of the world’s most iconic cheeses: Pamiggiano Reggiano in Italy, Emmental, Raclette and Gruyere in Switzerland, as well as French Comte, are all crafted in cheese vats made from copper. What difference does copper make in these cheeses? To find out, we tracked down one of the only American cheesemakers making cheese in a copper vat: Master Cheesemaker Bruce Workman at Edelweiss Creamery near Monticello, Wisconsin.

We caught Bruce last week when he was operating on only about three hours of sleep over the course of two days. That’s because the computer that helps run much of his equipment had broken down the day before, and he was still trying to catch up. But he was happy to sit down, take a break and talk cheese.