Blueberry-Lemon Whole Wheat Muffins:
Prepare as above, except substitute 1 teaspoon finely shredded lemon peel for the 2 teaspoons finely shredded orange peel and use 3/4 cup buttermilk total for the 1/2 cup buttermilk and 1/4 cup orange juice. Bake as directed.
*Test Kitchen Tip:
To make 1/2 cup sour milk, place 1-1/2 teaspoons vinegar or lemon juice in glass measuring cup. Add enough milk to make 1/2 cup total liquid; stir. Let stand for 5 minutes before using.