With its delightful tang, subtle richness, and tenderizing capabilities, buttermilk has so many uses in cooking and baking. This dairy-case staple has so much culinary potential—it tenderizes poultry, ...

So what is it then? Take a look through Grandma's old recipe box, and you might notice that many old-fashioned Southern recipes call for sour milk as well as buttermilk. From the best biscuits to ...