When you're baking and run out of milk, there are some surprising substitutions you can call on; one of them is sour cream. Sour cream is an acceptable replacement for whole milk, buttermilk or evaporated milk in baking. Regular and reduced-fat are preferred over nonfat in baking because the latter will separate. Sour cream adds a creamier texture to baked goods because of its acidity. Sub it in at equal parts, but it might require adjusting the quantities of other ingredients.
Adjust the level of shortening or butter in the recipe. If the sour cream is thick or heavy, reduce the shortening by 1/2 cup; if the sour cream is thin or light, reduce the shortening by 1/3 cup.
Revise the amount of baking soda and baking powder when substituting sour cream. For each cup of sour cream, add 1 teaspoon of baking soda to the dry ingredients, and reduce the baking powder by 1 teaspoon.
Follow the baking time according to the recipe. Insert a toothpick into the middle of the baked item, and remove the food from the oven when the toothpick comes out clear.