I wouldn't think you would want to scald breastmilk as that would likely
denature (cook) the proteins.  I think denatured proteins would not have
the same specificity for action and would be useful only for their amino
acid content.

I have a mom who has complained  for many months of sour milk upon
storage. She was transporting it in a cooler bag containing several
frozen cooling elements.  She tried transporting it on ice and found
that it did not get sour!  May be it stays chilled better....

Cathy Bastian, RD, IBCLC