During ghee making, milk solids (primarily lactose and proteins) caramelize and brown due to heat. They are then removed through straining after the ghee is clarified.
Ghee is clarified butter, made by simmering butter to remove water and milk solids. The process involves several stages:
Melting: Butter is heated in a pot. Initially, it melts into a liquid state.
Separation: As the butter simmers, the water content evaporates. Milk solids, consisting mainly of lactose (milk sugar) and proteins (like casein and whey), begin to separate from the butterfat.
Caramelization: The milk solids, being exposed to high heat, undergo Maillard reaction and caramelization. This is what gives ghee its characteristic nutty flavor and golden color. They gradually turn brown and settle at the bottom of the pot.
Clarification: The butterfat becomes clear and transparent as the water evaporates and the milk solids settle. This clarified butter is the ghee.
Straining: Once the ghee is cooled slightly, it is carefully strained through a fine-mesh sieve or cheesecloth to remove the browned milk solids from the clarified butterfat. This ensures a smooth and pure ghee.
Don't overheat the ghee at the end of the process. Overheating can burn the milk solids, resulting in a bitter taste and dark color. Aim for a gentle simmer and remove from heat once the milk solids have settled and the ghee is clear.