What is the foam that forms on top of melting butter when making ghee, and should it be removed?

Question

See that foam on your melting butter? Find out what it is and whether you should skim it off or leave it alone during the ghee-making process.

Answer 1

The foam that forms on top of melting butter when making ghee is primarily composed of milk solids and impurities. It should be removed to achieve a pure, clarified ghee with a longer shelf life and a cleaner flavor.

Detailed Explanation:

When butter is heated to make ghee, the water content evaporates, and the milk solids (proteins and lactose) separate from the butterfat. These milk solids, along with any impurities present in the butter, rise to the surface and form a foamy layer. This foam will initially be white and frothy, but as the process continues, it will turn golden brown and eventually settle at the bottom of the pot.

Removing this foam is crucial for several reasons. First, it prevents the milk solids from burning and imparting a bitter or burnt taste to the ghee. Second, the presence of milk solids can reduce the ghee's shelf life, as they can promote spoilage. Finally, removing the foam results in a clearer, purer ghee with a more delicate and desirable flavor profile.

To remove the foam, use a spoon or fine-mesh skimmer to gently scoop it off the surface as it forms. Repeat this process throughout the ghee-making process until the foam stops forming and the ghee is clear and golden. Be careful not to disturb the sediment that settles at the bottom of the pot.

Pro Tip:

Use unsalted butter to make ghee. Salted butter contains additional milk solids and impurities that can affect the flavor and clarity of the final product, and may cause more foam to form.