Steaming Milk: How to Get Velvety Microfoam

Froth Is Not Microfoam

The coarse, bubbly layer on a cappuccino and the glossy, paint-like texture under good latte art are not the same thing. The second one is microfoam: air bubbles so small you cannot pick them out by eye, dispersed through the milk.

The difference is entirely technique. Same milk, same machine, different result.

Pitcher and Milk

Fill the pitcher one third of the way. More and it will overflow; less and you cannot form a whirlpool. Start with cold milk — warm milk shortens your aeration window.

Whole milk is the most forgiving. Skimmed milk can produce microfoam too, but the margin for error narrows. Among plant milks, barista editions behave far more predictably.

Two Distinct Stages

Steaming is two jobs, and the order matters:

• Aeration: keep the wand tip near the surface. You will hear a soft hiss. That sound means air is entering the milk, and it should last only the first 3–4 seconds.
• Whirlpool: tilt the pitcher and sink the tip slightly so the milk starts spinning. This stage breaks the bubbles down and smooths the texture.

If the hissing carries on past those first seconds you are adding too much air, and you will be left with froth rather than microfoam.

The Temperature Ceiling

Aim for 55–65 °C. Without a thermometer, use the outside of the pitcher: the moment it becomes uncomfortable to hold is roughly 60 °C.

Past 70 °C the milk proteins break down. The taste turns cooked and flat, and the foam collapses. There is no recovering from it — start that milk again.

Just Before Serving

Tap the pitcher on the counter a couple of times, then swirl it. Large bubbles pop and the surface turns glossy. Do not let it sit: microfoam begins separating within half a minute.

Quick Checklist

1. Pitcher one third full, milk cold.
2. Aerate for 3–4 seconds, keep the hiss short.
3. Whirlpool spinning, sound smoothing out.
4. Stop around 60 °C.
5. Tap, swirl, pour straight away.