Almost 1 cup milk
1 Tbsp White vinegar
Pour 1 Tbsp white vinegar in a measuring cup. Pour in milk until it reaches the 1 cup mark. Stir to combine. Wait 5 minutes. Viola! Buttermilk!
Discovering this has been so wonderful. No more quick trip to the store. No more buttermilk going bad (which it always seemed to before its expiration date). I can make my favorite buttermilk waffles anytime. This is just so easy. I am never buying buttermilk again.