It is normal for breastmilk to have a layer of butter after freezing. The yellow layer of grease on the surface of breastmilk is a kind of natural milk fat, which will melt after heating. The yellow oil on the surface of breastmilk is a natural milk fat, which will melt when heated. A layer of butter on the surface of breastmilk after freezing is the result of the separation of water and fat after the precipitation of breastmilk, which is milk fat. It is also possible that breastfeeding women’s diet is more greasy, resulting in more breast milk fat, which is generally normal, and breastfeeding women are advised to eat a light diet. However, after freezing breastmilk, you should pay attention to observe whether it is spoiled, if there is a change in taste, color, etc., you should be alert to breastmilk spoilage, spoiled breastmilk should not be given to infants to consume, it can not be supplemented with nutrients, and may also lead to discomfort in infants. It is recommended to use fresh breastmilk to feed your baby.