Frozen breastmilk

Mo • Wed, Nov 08

I’ve been starting to pump to build a supply for when I go back to work. I have been freezing in 6oz portions because I feel like I’m wasting a bag if I don’t fill it up! But, should I be doing some bags at 3oz? Can they unfreeze 6oz and only feed 3oz and then wait hours later and use the other 3oz? Or will it be bad by then?