What, exactly, is buttermilk?!
Traditionally, buttermilk is the liquid that is leftover after churning butter. It's low in fat and contains most of the protein originally in the milk. True buttermilk ferments naturally into a thick, tangy cream.
These days, buttermilk is usually made by introducing a bacteria culture to low-fat milk and then heating the mixture. We've never had naturally fermented buttermilk, but we hear that commercially-made buttermilk is thicker and tastes more tart than the traditional stuff.
Can anyone who's had "real" buttermilk confirm?
(Image: Emma Christensen for the Kitchn)