Technique: Creating Maple Buttermilk Vinegar at Chicago’s The Wit

We got raw maple sap straight out of the tree, before it was cooked down or anything. It was one of those things where I was like, ‘Just give me maple sap, and then I’ll figure out what to do with it.’ We got six gallons, but we didn’t know what we were going to do with it or how to use it.

We started by cooking it over a double boiler. I didn’...