Ice cream structure

Ice cream is a frozen foam. The mix of milk, cream, sugar and flavoring is first homogenized, forcing it through small openings to break the fat into tiny particles that stay evenly mixed instead of separating. It is then frozen into a semi-liquid paste, with air beaten in while it freezes, and finally hardened.

The air is called overrun, the percentage increase in the volume of the mix from the beating in of air. Too little makes ice cream dense and heavy, while too much leaves it snowy and dry. US rules require a minimum weight per gallon to limit excess air.

Fat, milk solids, sugar and small amounts of stabilizer all hold the structure together. Stabilizers help prevent large ice crystals, which keeps the texture creamy and the scoop smooth rather than icy.