The thickness of buttermilk can vary significantly from one carton to another. You might need to adjust the amount used for a particular recipe. Photo by Travis Rainey, Prop Styling by Tim Ferro. What is the best buttermilk to use for baking? Cheryl Day, a cookbook author, describes herself as a “buttermilk purist.” When she bakes, she uses cultured buttermilk made from whole milk that is nonhomogenized and free of additives. “It’s low-temperature, vat-pasteurized,” she says, praising its rich mouthfeel. I get it from a nearby dairy where the cows are content. Those particulars make all the difference.
