Why can't you add warm to cold breast milk?

*H&J*

I know you aren't supposed to but I can't seem to find a good answer for why.  Is it just b/c you can introduce more bacteria?  And is freshly expressed breast milk considered warm?  I always figured so but never really thought more on the subject.

aynjc

I think you can if you are going to use it in the next 24 hours.  I'm not sure why??

rommelea

It's because BM shouldn't have a drastic change in temp. - or at least that's what the LC at my mommy's group told us.  Yes, fresh expressed milk is considered warm. 

FYI: She also told us it shouldn't go from boob to freezer, to put it in the fridge first - gradual changes are better... also freezer milk should be thawed in the fridge.

Lotte134

Because it will warm the cooled milk.  Once the cooled milk has been warmed it should be used up within 24 hours or something like that.  Basically you just want to refrigerate the freshly expressed milk and then combine.

*H&J*

I get the reasons "because it changes temp of cooled milk", etc, I guess I was looking for a more scientific reason.  Does it keep changing the properties of antibodies, introduction of bacteria, those types of reasons.  I can't really find any scientific explanation when I google it, just that you aren't supposed to do it. 

TessaTru

The nurse that did a home visit when DD was first born told me that it caused bacteria growth, and to cool all milk before combining it.