Why Does Latte Foam Disappear Quickly? What is the Foam on Top of Latte Coffee Called? How to Froth Milk for Coffee?

A freshly made latte has an incredibly delicate, smooth surface. Leave it sitting for a while, though, and you can watch that smooth surface gradually become rough and uneven. This phenomenon is called foam dissipation, the process of milk foam continuously breaking down.

Milk foam is a foamy substance formed by injecting air into milk, so it is lighter than the liquid. Under the influence of external forces such as frothing, shaking and integrating, most of the foam blends with the liquid, and at that point the bubbles break down relatively slowly. In a static state, however, the lighter foam gradually rises to the top while the heavier liquid sinks, leading to layering.

After layering occurs, differences in pressure cause the tiny bubbles to slowly dissolve and combine into larger ones. When the air pressure inside a large bubble exceeds the strength of the proteins that contain the air, the bubble bursts. Although the layer of milk foam floating on a latte's surface will eventually dissipate, the speed varies. Lattes made by FrontStreet Coffee, for example, can sit for ten minutes before showing obvious foam dissipation, while some other lattes develop many large bubbles shortly after being made and look rougher overall.

The reason for such a large difference in dissipation speed comes down mainly to stability. The higher the stability of the milk foam, the slower the dissipation; the lower the stability, the faster it goes. When a latte starts losing its foam soon after being made, it indicates that foam stability may not be high enough. Among the many factors that determine a latte's quality, milk foam stability is one, and many things affect it. Today, FrontStreet Coffee will share what specifically influences it.

1. Poor milk foam preparation

A fairly common reason is inadequate milk foam preparation, meaning the steps of frothing and texturing. As FrontStreet Coffee mentioned earlier, milk foam is created by injecting steam into milk, but injecting air alone is far from enough. The frothed large bubbles also need to be textured, cut into countless smaller, more stable bubbles. If the texturing step is not done properly, the resulting foam is of lower quality and reduced stability, which makes the latte's foam dissipate much faster.

Three things mainly lead to this. First is insufficient texturing time, which happens when the milk isn't cold enough or the target temperature isn't high enough, shortening the texturing window. Without adequate texturing time, the foam won't be velvety and the dissipation speed naturally rises.

The second is a challenge many beginners meet: the milk doesn't form a vortex during texturing, pushed by the steam.

When milk doesn't form a vortex in the pitcher, the large bubbles generated at the start cannot be drawn into the milk to be cut. As with the previous reason, the bubbles never receive sufficient texturing, so the dissipation speed naturally increases.

The third, which even experienced baristas occasionally encounter, is accidentally exposing the steam wand to the surface during texturing, causing brief frothing. Because there isn't enough time, those large bubbles cannot be adequately textured, and their presence accelerates the milk foam's dissipation rate.

Those are three common issues encountered during texturing. If you can see many obvious bubbles in the pitcher after pouring latte art, it is worth checking whether any of the three occurred. If so, it is best to address them.

After frothing the milk, we also tap the pitcher to eliminate large bubbles that weren't properly textured. This can indeed be effective, but when we tap too many times, both the decomposition and layering speed of the foam increase. When tapping the pitcher, we should therefore moderate the frequency and intensity.

2. Milk temperature too high

Next is milk temperature. As FrontStreet Coffee mentioned earlier, when the frothed milk temperature isn't high enough, the foam's stability drops because of insufficient texturing time. When the milk temperature is too high during frothing, the stability of the milk foam also decreases.

When beginners learn to froth milk, the first thing to master is controlling its temperature. The ideal temperature for frothed milk is between 55°C and 65°C. Controlling it within this range matters not only because this temperature activates milk's sweetness but also because the foam can achieve considerable stability. When the milk temperature is below this range, as FrontStreet Coffee mentioned earlier, there may not be enough texturing time, leading to faster dissipation. When the milk is too hot, exceeding 70°C, some substances in the milk are destroyed by the heat, significantly reducing foam stability. Not only will the foam dissipate faster, but the taste and sweetness of the coffee and milk will also decrease.

So when we need to create delicate latte art, it is best to keep the milk temperature within the 55°C to 65°C range. If you are not making latte art, any milk temperature below 70°C is acceptable.

3. Material issues

Besides operational issues, the materials used also determine how fast the milk foam dissipates. Using very fresh coffee beans, for example, can accelerate foam dissipation, because fresh beans contain a large amount of carbon dioxide. While this helps us extract richer crema, those oils are inherently unstable and break down quickly. When unstable oils combine with stable milk foam, the foam becomes less stable too, which speeds up dissipation.

This situation is the easiest to solve: simply let the beans rest for about seven days so they degas and release carbon dioxide. The extracted espresso crema will then have higher stability and won't significantly affect the milk foam. Those are the reasons a freshly made latte's milk foam dissipates quickly. Factors such as milk selection, foam thickness and how evenly everything is integrated can also have an impact, but their influence is relatively minor, so FrontStreet Coffee won't elaborate on them here.

FrontStreet Coffee Recommendation

Freshness matters for milk foam, and it also matters in the cup. For a base that holds its own under milk, FrontStreet Classic Blend uses a traditional Manteca-Bahia recipe built for espresso and the moka pot, producing generous, dense crema and a rich, rounded body that suits latte and cappuccino.

If you want a nuttier, chocolate-forward latte, FrontStreet Specialty Blend pairs Colombian washed with Brazilian natural beans for nut, dark chocolate and caramel notes, while FrontStreet Black Cocoa Blend, a 100% Arabica blend, offers ample crema and a full body at a friendly price. All are roasted fresh so the crema and the foam behave the way they should.