Did you know that there's no butter in buttermilk? There's no turtle in a turtleneck either. But, buttermilk has a sour flavor similar to yogurt, which makes it an important ingredient in many baking recipes like sweet breads and cakes.
The recipe calls for buttermilk but there's none in the fridge? No need to change your plans. To make 1 cup buttermilk, put 2 tablespoons lemon juice in a glass measuring cup. Add enough low-fat milk (1 or 2 percent) to equal 1 cup. Let sit 15 minutes. The acid in the juice adds a tang to the milk, mimicking the flavor of authentic buttermilk.