I've stored a bottle of breastmilk in the fridge, taken it out and warmed it up, but my baby doesn't finish it all. What can I do with it? Can I leave it out for the 6 hours and let her finish it later, put it back in the fridge, or am I suppose to just throw it away? It seems such a waste to throw away any milk. What do you do or what am I suppose to do? Thank you.