How To Tell If Your Breastmilk Is Spoiled
Breastmilk contains hundreds of components including minerals, vitamins, proteins, carbohydrates, and fats. This mixture naturally separates into a fatty and less dense layer, when chilled or frozen. When thawed, if the milk does not mix back together to a homogeneous appearance and leaves chunks or floating pieces, it could be spoiled.
Another indicator would be smell and taste.
Sour & rancid. YUCK.
If it’s instead a bit metallic or soapy smelling/tasting, it may have high lipase. This is safe to feed, but if your baby doesn’t like the taste, fresh milk can be scalded. Another post coming on that.
Appearance, smell, taste and consistency should give you some good indicators if your milk is unsafe to feed. Always use your best judgement.