Frozen buttermilk = genius! Whenever I have a recipe that calls for buttermilk it kills me because it's essentially the same price for a few ounces or a quart, but I don't need a whole quart! Consequentially I avoid buttermilk requiring recipes on the principle of unfair pricing. Until now! I saw this pin - and my relationship with buttermilk is forever changed! It's so simple, just freeze buttermilk in ice cube trays. They are rather difficult to get out, when I do this again (because I do this forever now!) I'll make sure to not fill the ice tray too full so the cubes won't get stuck together in unbudging brick. Once you get one cube out it gets easier.
Also, be sure to remember that you've occupied the ice trays, otherwise your husband might be annoyed when he wants ice :).