You really can substitute sour milk for buttermilk. I had always heard this was true, but I was never brave enough to try it for myself. But, when we had a whole gallon of whole milk go bad after Thanksgiving, I couldn't bring myself to pour it all down the sink. (Dwayne bought it to make rice pudding, but never got around to it.) So, I made myself brave enough to try using the sour milk in place of buttermilk and to my surprise, I made the most dee-lish pancakes and scones that way. I plan to whip up another few batches of pancakes tonight while I am in the kitchen making dinner anyway and freeze 'em for the girls' breakfasts. I'm pretty thrilled at the fact that I'll never have to pour outdated milk down the sink again. Instead of wasting it, I'll just whip up some more pancakes or something like that.