foamedmilk

Foamed milk refers to milk that has been aerated to incorporate air, creating a light, velvety foam with increased volume. In dairy milk the foam is stabilized by milk proteins, primarily casein and whey, and to a lesser extent fats. Heating milk to around 60–65°C helps these proteins unfold and form a cohesive network around the air bubbles, producing a smooth texture. Fat content influences mouthfeel and stability: whole milk generally yields creamier foam, while skim milk forms lighter, finer foam. Plant-based milks such as soy or oat can also be foamed, though their stability varies and may require stabilizers or additives.

Foam quality is often described as microfoam or macrofoam. Microfoam consists of very small, uniform bubbles producing a glossy, silky texture suitable for latte art. Macrofoam contains larger bubbles and a drier texture, which can be preferred for certain espresso drinks. The type of foam is influenced by the milk’s composition, the foaming technique, and the equipment used. Over-aeration or overheating can cause foam to collapse or become unstable, and temperatures above about 70°C can degrade texture.

Common methods to produce foamed milk include steam wands on espresso machines, dedicated milk frothers, and hand or mechanical frothing devices. Foamed milk is a staple in many beverages such as lattes, cappuccinos, flat whites, and certain hot chocolates, where it serves both textural and sensory roles. It is also used in culinary applications to add lightness to desserts and sauces.