Step 1

Add 1 tablespoon of lemon juice or vinegar to a measuring cup.

Step 2

Pour milk to the 1-cup line (use this same ratio of lemon juice/vinegar to milk when you need more or less than 1 cup of buttermilk). Stir to combine the liquids.

Step 3

Let the mixture sit for about 10 minutes. You’ll begin to see small curdled bits in the mixture; this means it’s ready to add to the recipe. Even if you don’t see much change in the appearance of the mixture, the acid has been added to your milk and will work just like the store-bought version.