Step 1

Pour milk into a one-cup measuring pitcher, stopping just shy of one full cup.

Step 2

Add one tablespoon of fresh lemon juice or white vinegar to the milk. If you need to add another splash of milk to the pitcher, do so to make sure you have one full cup of liquid.

Step 3

Stir the milk and lemon juice to mix well.

Step 4

Allow the mixture to sit and curdle for 10 minutes. Then stir again and use as needed.