What is "milk skin"?

Milk skin, also known as "cream skin" or "milk film," refers to the thin layer of protein that forms on the surface of heated milk when it cools down. It is created by the alteration of proteins in the milk, which causes them to thicken and form a thin, translucent layer. Milk skin is often removed before using the milk in recipes or consuming it directly, as it can have a slightly different texture and taste compared to the rest of the milk. However, some people enjoy the delicate texture of milk skin and leave it intact or use it as a garnish in certain dishes.