Foam that is thin or absent means air was never successfully incorporated.
Not enough stretching
A cappuccino needs 5 to 6 seconds of air at the surface — noticeably more than a flat white.
If you are stretching for two seconds out of habit, you will get flat white texture in a cappuccino cup.
Listen for the hissing or tearing sound. No sound means no air.
The tip is too deep
The tip must be just under the surface to draw air. A centimetre too deep and it is simply heating the milk.
Position it at the surface, then lower the jug very slightly until you hear the hiss.
Milk started too warm
Air can only be incorporated below about 37 °C. Milk that started at 15 °C rather than 4 °C gives you a much shorter window.
Keep milk in the fridge until the moment you steam it.
Milk too old
Protein degrades over the milk’s life. Milk near its date foams poorly regardless of technique.
Skimmed milk
Counterintuitively, skimmed produces more volume of stiffer, drier foam that collapses faster. Whole milk gives less volume and much better stability.
If your foam looks good and dies in the cup, this is a likely cause.
Weak steam
Thermoblock machines produce modest steam. Steaming a smaller volume of milk compensates considerably.
Last reviewed 8 August 2026