Microfoam is milk with bubbles so small the foam behaves like a liquid. It pours, integrates with espresso and makes latte art; only a steam wand produces it.

What Is Microfoam in Steamed Milk?

Microfoam is steamed milk whose bubbles are small and uniform enough that the foam behaves as part of the liquid rather than as a separate layer.

The surface should look like wet paint: glossy, moving, with no visible individual bubbles.

Foam versus microfoam

Foam has large bubbles. It sits on top of a drink, it can be spooned, and it separates within a minute or two. That is what automatic frothers produce, and it is correct for a traditional cappuccino.

Microfoam pours. It goes into the drink and stays integrated, giving a uniform texture from the first mouthful to the last. It is what a flat white is named for and what latte art requires.

How it is made

Two phases, and the second is where microfoam happens.

Stretch briefly — three to five seconds with the wand tip just below the surface, drawing air in. That gives you foam with large bubbles.

Spin for considerably longer, with the wand deeper and off-center so the milk rotates as one vortex. That breaks the large bubbles into small ones and folds them through the liquid.

Most people stretch too long and spin too little, which is why they get foam rather than microfoam.

What it is made of

Air bubbles of roughly 10 to 100 micrometers, each wrapped in a film of denatured casein and whey proteins, which heat unfolds and sends to the air-water boundary, and coated by fat globules that give the mouthfeel and slow collapse. Bubbles that small sit below what the tongue can feel, so it reads as a richer liquid rather than a foam. Below about 37 °C (99 °F) the proteins can still wrap new bubbles; above about 70 °C (158 °F) they are spent, which is why the stretch comes first and the steaming stops near 65 °C (149 °F). Even perfect microfoam separates within a couple of minutes, so pour promptly.

What you need

A steam wand. No automatic frother produces microfoam, because none of them can spin the milk the way a wand does.

Last reviewed 30 October 2026

Keep reading

What size milk pitcher should I buy?
Choose a milk pitcher about twice the volume of the milk: a 350 ml (12 oz) pitcher for one drink and about 600 ml (20 oz) for two. Stainless steel only.
Cappuccino or cortado — what is the difference?
Ratio and foam. A cappuccino is about a third foam in a 150 to 180 ml cup; a cortado is espresso cut with an equal volume of warm milk and almost no foam.
Foam or froth — is there a difference?
Foam and froth mean the same thing in coffee. The real difference is between large-bubble foam you can spoon and microfoam that pours like liquid.
Which milk alternative is best in coffee?
Barista oat milk is the best plant milk for coffee, then barista soy. Barista versions add fat and stabilizers, which is why they foam and resist curdling.
Which milk fat percentage is best for coffee?
Whole milk is the best fat percentage for coffee: protein builds the foam and fat gives body and stability. Skim foams more, but dry, stiff and short-lived.
What milk is best for latte art?
Whole dairy milk, cold, in a sharp-spouted pitcher. Fat stabilizes foam and protein builds it; skim has protein without fat, so it foams fast and pours badly.