The milk foams but never becomes microfoam
The milk produces plenty of foam, but it is airy and bubbly and never turns glossy, however carefully it is steamed.
Applies to: Espresso machine, Flat white, Latte
Why foam stays coarse instead of turning silky
CoffeeHQ explanation
Microfoam is not a different substance from ordinary foam. It is the same air, divided into bubbles too small to see. Getting there takes two things in sequence: a short spell of adding air while the milk is cold, and then a much longer spell in which the milk spins in a whirlpool and the large bubbles are sheared into smaller and smaller ones. Foam that stays coarse had the first phase without enough of the second.
Three things cut the second phase short. Air that keeps going in for too long leaves no time to work it down. A jug held so that the milk merely churns, with no steady rotation, never shears the bubbles. And a wand that pulls in its own air, the plastic-sleeved kind fitted to many home machines, adds air for as long as it runs, so there is no second phase at all.
Causes, most likely first
There are 4 likely causes, listed with the most probable first. Work down the list and change one thing at a time, so that when the problem goes away you know which change fixed it.
Cause 1 of 4 · Commonly the cause
A pannarello or assisted wand
- How to check
- Is there a plastic collar around the metal wand, with a small hole in the side?
- What to change
- The sleeve introduces air automatically through a side hole, so you cannot control how much goes in or when it stops — which is what microfoam requires. On most machines the sleeve pulls off, exposing a conventional tip underneath; check the manual first, because on some it is part of the steam path.
Cause 2 of 4 · Commonly the cause
Air introduced for too long
- What to change
- Add air only in the first few seconds while the milk is cold, then submerge the tip and spend the rest of the time on the whirlpool.
Cause 3 of 4 · Commonly the cause
No whirlpool forming
- What to change
- The spinning phase is what shears large bubbles into small ones. Find the wand position where the whole jug turns, and hold it still.
Cause 4 of 4 · Reported, not independently verified
A milk that cannot hold fine foam
- What to change
- Standard plant milks frequently cannot, whatever the technique. Test once with whole dairy milk or a barista formulation to separate the milk from the method.
If none of these fixes it
Check the cleaning and descaling guide. Equipment that needs maintenance can cause several of these symptoms at once, and no change of recipe will correct it.
Work through it for your setup
The causes above are general. These go to the part of a diagnostic that takes this symptom one check and one change at a time.
- Large bubbles on top, and thin milk underneathThe possibilities, the quickest check and one thing to change first
- The milk will not roll into a whirlpoolThe possibilities, the quickest check and one thing to change first
- Milk faults, one at a timeEvery flow in this diagnostic, side by side
Shorten the air, lengthen the spin
On the next jug, let air in for only the first few seconds, until the jug just stops feeling cold to the hand, then lower the tip slightly and tilt the jug until the milk turns as a single whirlpool. Hold it there, silent apart from a low rumble, until the milk reaches temperature. If you cannot get a whirlpool, move the tip off-centre and nearer the side of the jug, and check the jug is between a third and half full.
When the wand or the milk will not allow it
An assisted wand with an air-intake sleeve is built to make foam without skill, and what it makes is cappuccino foam. Some sleeves can be removed to expose a plain tip, which then behaves like any other wand; your manual will say. Milk can also be the limit: some plant drinks, and dairy milk whose fat has begun to break down in storage, will not hold fine bubbles however they are steamed. Try a fresh carton of whole milk before changing anything about your hands.
Easily confused with
- Visibly bubbly milk — Large bubbles on the surface mean air went in late or violently. Milk that is foamy throughout but never glossy had enough time and no whirlpool.
- Stiff, dry foam — Stiff foam has too much air in it. Microfoam needs less air than most people add, not better air.
- A weak wand — A weak wand can still make microfoam in a small jug; it is slower. If the milk will not spin at all, look at steam power.
What not to change at the same time
Do not change the milk and the technique on the same jug. Steam one jug of a milk you know works, with the new timing, before concluding anything about either.
How to tell it is fixed
Swirled in the jug, the milk moves as one liquid, shines like wet paint and shows no bubbles. Poured, it leaves the jug as a single stream, not milk followed by a cap.
Milk frothing troubleshooter — Choose 'no microfoam', then your milk and how you froth it. It checks the milk and the limits of the equipment before it suggests a change to technique.
Related issues
Work it out
Interactive tools that take you through this one change at a time.