Steamed milk is too bubbly or has large bubbles
Milk foam looks coarse and airy with visible large bubbles rather than smooth, glossy microfoam.
Applies to: Espresso machine, Cappuccino, Latte, Flat white
Safety note
The steam wand and the milk jug both get hot enough to burn skin quickly. Keep hands clear of the wand tip while steam is flowing, and use a cloth or handle rather than gripping the jug body directly once it's warm.
Why steamed milk comes out bubbly
CoffeeHQ explanation
Good milk foam is made in two stages. First air is drawn in at the surface, which makes bubbles of all sizes. Then the milk is spun, and the turbulence breaks the large bubbles into ones too small to see. Bubbly milk means the second stage did not finish the job: air went in, and it was never broken down.
That happens for one of three reasons. Too much air was added, more than the spinning could deal with. Or it was added too late, when the milk was already hot and there was no time left to work it. Or the milk was never spinning properly, because the wand was in the wrong position or the jug too full or too empty for a whirlpool to form. Large bubbles are also unstable, which is why this kind of foam collapses and separates within a minute.
Causes, most likely first
There are 2 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 2 · Commonly the cause
Air introduced too aggressively or for too long
- How to check
- Does the foam look coarse from early on, or only after steaming for a while?
- What to change
- Introduce air only briefly at the start, then focus on spinning the milk to break bubbles down into microfoam.
Cause 2 of 2 · Reported, not independently verified
Wand tip position creating large bubbles instead of a fine vortex
- What to change
- Adjust wand tip depth and angle to create a steady spinning vortex rather than surface splashing.
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
How it shows up on different brewers
Tendency, not a guarantee
- Steam wand
- Add air only in the first few seconds, while the jug is still cool to the touch, then lower the tip just under the surface and off-centre so the milk rolls.
- Wand with a pannarello sleeve
- The sleeve draws air in for the whole time it is near the surface. Sink it deeper once the milk has expanded a little.
- Automatic and handheld frothers
- Whisks make coarser foam by nature. Tapping the jug on the counter and swirling removes the largest bubbles.
Easily confused with
- Foam that is too stiff — Stiff foam is fine-bubbled but too dry and thick to pour, from too much air worked in well. Bubbly foam has visible bubbles, from air that was not worked in at all.
- Plant milk separating — Curdling leaves grainy flecks in the liquid and happens when the milk meets the coffee. Bubbles are visible in the jug before any coffee is involved.
What not to change at the same time
Do not change how long you add air and where you hold the wand in the same attempt. Shorten the air stage first; it is the more common fault.
How to tell it is fixed
The surface should look like wet gloss paint, with no bubbles visible after a swirl, and the milk should pour as one fluid without foam being left behind in the jug.
Related issues
Work it out
Interactive tools that take you through this one change at a time.
Learn the technique
Step-by-step guides to the skills this problem comes from.
- Steaming milkProduce hot milk with a fine, integrated foam that pours as one liquid rather than as foam sitting on milk.
- Making microfoamReduce the air in steamed milk to bubbles too small to see, so the foam and the liquid behave as one substance.
- Frothing milk without a steam wandGet a usable milk foam using an electric frother, a whisk, a French press or a jar, and know what each can and cannot produce.