Microfoam

Microfoam, in coffee jargon, is a term used to describe an ideal standard for steamed milk. It is used for making espresso-based coffee drinks, particularly those with latte art. Although steamed milk can be made in a variety of ways, microfoam is by definition made using a steam wand on an espresso machine. It is created by denaturing milk proteins such as casein and whey; the protein attracts and holds gas on its surfaces, creating microfoam. Strictly speaking, microfoam is actually a very fine emulsion of denatured milk protein and air which has few or no visible bubbles.^{[citation needed]} The qualitative opposite of microfoam is macrofoam, which has visibly large bubbles, a style of milk commonly used for cappuccinos. During the steaming process, the foam phase naturally separates from the liquid phase, and rises to the surface. As a result, the pitcher is usually swirled in a smooth, circular motion until the mixture of foam and warmed milk becomes homogenous, before being added to a drink.