When butter is heated, it melts. When butter is heated these three components split apart from one another and settle into different layers. At the bottom of the heating vessel you will have a white cloudy substance; this substance is actually the milk solids and water.

How do you keep butter from separating?

Butter itself is an emulsion. When butter is heated and begins to melt, this emulsion breaks — the butterfat naturally separates from the milk solids and water. But you can prevent this by whisking the cold butter into a little hot water while it melts, thus creating a melted emulsion of butter.

Is melted butter supposed to separate?

This is perfectly normal and nothing to worry about and if you are using the melted butter to make a sweet or savoury recipe then you can just add the whole lot in, unless the recipe asks for clarified butter. Clarified butter (sometimes known as drawn butter) is the butterfat only.