I personally wouldn't trust the buttermilk. I use lemon juice forever, though. You can make soured milk with the lemon juice in place of the buttermilk- put one tablespoon of lemon juice into your one cup measuring cup and fill the rest with milk and allow to sit for 10-15 minutes. Stir before using. :-) This can be used in place of buttermilk and the taste is very, very close.
at 3:41 PM on Apr. 9, 2010