In a 1-cup measuring cup, add 1 Tablespoon of fresh lemon juice. Top the lemon juice with with skim, low fat or whole milk. Stir and let sit for two minutes. After two minutes, your milk is both acidic and curdled. Perfect!
Yogurt and Milk
Mix 3/4 cup plain yogurt with 1/4 cup of milk. Stir and make it a quick substitution for buttermilk.
Milk and Cream of Tartar
Mix 1 cup of milk with 1 3/4 teaspoon cream of tartar. To ensure that the mixture doesn’t get lumpy, mix the cream of tartar with 2 Tablespoons of milk. Once mixed add the rest of the cup of milk. Cream of tartar is an acid and will simulate the acidic environment of buttermilk in a pinch.