Ask Lisa: How do you sour milk?

Q: I have a recipe that calls for buttermilk. Can I use sour milk instead, or kefir? If so, how do I sour milk?— Lyn Lombard Palka, Columbus, OhioA: Sour milk or kefir can be substituted for buttermilk.For kefir, substitute it cup for cup for the buttermilk.To sour milk, place 1 tablespoon of vinegar or lemon juice in a 1-cup measure and add enough milk (whole or low-fat) to equal 1 cup.Other substitutes for buttermilk include sour cream, yogurt or a combination of half [...]