Step 1

Combine the milk or cream and acid. Stir the milk or cream and lemon juice or vinegar together in a measuring cup.

Step 2

Let stand 5 to 10 minutes. Let the mixture stand at room temperature for 5 to 10 minutes. When it is ready, the milk will be slightly thickened and you will see small curdled bits. This substitute will not become as thick as regular buttermilk, but you will also not notice the curdled bits in your finished recipe.

Step 3

Use the buttermilk. Use this substitute (including curdled bits) as you would buttermilk in your recipe.