yes, it is the action of the lipase that changes that taste/smell of the milk,
but it is NOT rancid. the mother needs to experiment with how much heating is
needed to reduce the smell, and it doesn't need to be heated if the baby will
take it as is (some won't). usually only gentle heating is needed, and
remember, the more heat, the more loss of the good ingredients takes place.

NOT rancid. just different.

carol brussel IBCLC