Definition
Buttermilk is a tangy, cultured dairy drink. It’s often thicker than regular milk and has a slightly sour taste. Think of it as the yogurt of the milk world. Traditionally, it was the liquid left over after churning butter. Nowadays, it's usually made by adding cultures to low-fat milk. It's a popular ingredient in baking, adding moisture and a tender crumb to recipes. It's also enjoyed as a refreshing drink, especially in warmer climates.