Thanks! But I'm not sure I'm finding my exact answer in that link. That link is regarding re-using left over milk from a feeding for another feeding. I want to know if I can put an entire unused bottle back in the fridge after it has warmed to room temperature (a bottle that was never frozen, btw... it was in the fridge since this morning when I pumped it). Maybe this answers my question, though: "...it would seem to me that expressed
breast milk, fed to the baby, partially consumed, and then refrigerated,
could be used for one more feeding no more than four hours later." Even though she's talking about partially consumed and I am talking about unused, is she saying my bottle can go back in fridge but must be used in 4 hours?