Barista course · Episode 7

Steaming milk properly

The full text of this episode — to read, look up and quote.

Cold open

Look at this. It shines like wet paint and flows like silk. This is not foam with big bubbles, the kind a spoon makes.

This is microfoam. Velvety, fine-pored, sweet. That is exactly what you want.

And it is easier than it looks, once you understand two things. When to let air in, and when to stop.

Where this sits in the five Ms, and the physics

The fifth M again. Your hands. With milk foam two things happen one after the other.

First, you draw air into the milk. That turns liquid milk into volume and foam. Second, you roll that air into very fine bubbles until nothing coarse is left.

Air in first, then roll it fine. In the wrong order, or for too long, and you have coarse bubbly foam instead of silk.

Chart: the three phases

Three phases, and a pleasure to listen to. Watch closely, because you steer this with your ears. Phase one, stretching.

Cold milk into the jug, up to about where the spout begins. Hold the steam wand just below the surface and open it up. Now you hear a gentle, regular hiss.

Like a quiet kissing sound. Every hiss is a small sip of air going in. This is where your volume grows.

Lower the jug very slowly as the milk rises, so the wand always stays just below the surface. Phase two, rolling. As soon as there is enough air in, usually after a few seconds, you dip the wand a little deeper and tilt the jug slightly.

Now the hissing stops. And the milk begins to turn. A whirlpool, a rich, velvety vortex.

It breaks every coarse bubble down into microfoam. This is the most important moment. Phase three, polishing.

When the surface shines like wet paint and no coarse bubbles are left, you are done. Steam off. Jug away.

And immediately, this is compulsory, wipe the wand with a damp cloth and blow it through briefly, so that no milk dries on.

Chart: temperature

That leaves the temperature, and you feel that with your hand on the jug. Your target is sixty to sixty-five degrees. Nicely warm, and the milk turns naturally sweeter.

You do not need a thermometer. Put your hand on the outside of the jug. As long as you can comfortably keep it there, all is well.

The moment it gets too hot to hold, you are almost too far. Steam off. Above seventy degrees the milk scorches.

It loses its shine and tastes of boiled milk. Better to stop a little too early than too late. Now you.

Hands-on

Cold jug, cold milk up to the spout. Wand just below the surface, open it up, and now listen to the hiss. Draw air for a few seconds, lower the jug slowly.

Then wand deeper, tilt the jug and find the whirlpool, until the hissing disappears and it just rolls richly. Feel the warmth with your hand. Does it shine?

Then off. Wipe the wand. Do that a few times.

Forget latte art at the beginning, practise the texture only. Glossy, silky, no coarse bubbles.

Common mistakes

Three stumbling blocks. One. Drawing air for too long — then you have stiff bubble foam that cannot be poured any more.

Stop as soon as there is enough volume, and roll the rest. Two. Getting it too hot.

You recognise scorched milk by the missing shine. Three. Not cleaning the wand after foaming.

Dried-on milk is the most common care mistake, and it ruins the next foam.

Recap and your task

Let us hold on to this. Stretch first, the hiss, then roll, the whirlpool, then polish until it shines. Sixty to sixty-five degrees, felt with your hand.

And clean the wand at once. Your assignment. Foam milk three times and chase one target only.

The wet-paint look. In the next episode we pour your first heart from it. Latte art.

omaneo — and YOU can do espresso.