How Do I Curdle Soy Milk With Lemon Juice?

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Original buttermilk is the liquid product that is left after making butter from cream. It has a higher acid content than regular milk, which causes a tart or sour taste. Adding an acidic ingredient -- such as lemon juice -- to regular milk or a non-dairy milk results in a type of buttermilk, which can be used in cooking and baking. Soy milk makes a good choice because it is high in protein.

Step 1

Measure the amount of original unsweetened soy milk called for in your recipe in a measuring cup.

Step 2

Add 1 tablespoon of lemon juice to every 1 cup of soy milk. If your recipe asks for 2 cups, use 2 tablespoons of lemon juice.

Step 3

Stir the soy milk and lemon juice together. Let the mixture sit at room temperature for 10 minutes. Use the soured soy milk as required in your recipe.