The reason for it is because it's sterilized and zip lock bags aren't.

if you do ziplock.....try freezer if you are going to freeze.....I had bad luck and had some leaks...but I also had leaks in other brands. @kirt

most ppl think they can only use that expensive stuff specifically made for breastmilk lol i can't even imagine spending that with how many i use

I never even thought about zip locks! That's so smart @crixxy @lumos.nox and @babyrossmommy that would probably be smart to.

Cheaper than formula. And Amazon has amazing deals

i use ziplock snack bags. so much cheaper