If you are tired of buying buttermilk for one recipe and then wondering what to do with the rest, I have a product for you!
This little buddy costs like $3 or $4 and can sit in your fridge for months (how many months? not sure, I've been using mine for at least six and it still is good). You just add it to the dry ingredients that you are using and mix in the amount of water it says on the back. I just barely realized it is supposed to be water you mix in instead of milk, but hey, it always turned out alright. Anyway, if you cook with buttermilk even once in a while this is way worth the investment, much cheaper than regular buttermilk.