Why does the milk foam of latte disintegrate? How to avoid the rapid decomposition of milk foam?

One of my friends asked, "Why do I break down the foam and show big bubbles in less than 2 minutes after I have just finished the coffee?" It is believed that all the friends who make milk coffee have had a similar experience. In this issue, baristas will analyze why this happens.

(start with a normal latte)

Coffee oil

Coffee oil is a very important factor in stabilizing milk bubbles. A cup of qualified Espresso oil is golden and delicate in texture. Coffee beans should not be too fresh. If coffee beans are too fresh and contain too much gas, they will make the oil too rich (thick).

(espresso oil made from too fresh coffee beans will be rough.)

And too fresh beans will be very unstable, pressed oil will be very rough, put for a long time will solidify and agglomerate. The latte foam made from this espresso is easy to break down. In many cases, the lattes made from exquisite milk bubbles are easy to break down into big bubbles because the coffee beans are too fresh.

(the surface of the beans decomposes quickly when the beans are too fresh)

Milk foam

Milk foam can be said to be the most important factor, and the fineness of milk foam directly leads to the stable time of milk foam. The finer the foam, the slower it decomposes. Dispense with milk foam can be divided into two stages, send and play, in which the rough milk foam has been sent to play delicate, specific operation can put the steam stick deep into the milk bubble layer, about the liquid surface of the 1cm, all steam holes are buried in the milk, through a direction of the whirlpool to beat the milk bubble to delicate, generally qualified milk bubble surface without coarse bubbles, showing reflective surface, good fluidity.

(milk foam should be delicate and smooth with good fluidity.)

Of course, the temperature of milk will also affect the rate of decomposition (layer) of milk bubbles. The ideal temperature for milk is between 55 and 65 ℃. If it is below this temperature, the sweetness of milk will not be excited as much as possible. If it is higher than this temperature, it will cause too much protein denaturation. That is, it will speed up the decomposition of milk bubbles.

Fusion technique

The degree of fusion of coffee and milk will also affect the decomposition rate of foam on the surface of latte. Generally, the higher the degree of fusion is, the more stable the result is, and the decomposition rate will be slow. If the fusion is not good, the coffee surface is rough, the structure is unstable, and it is easy to split into bubbles.

(bad integration)

It is generally believed that the best fusion is the uniform color of the liquid surface (gold ring) and the delicate and smooth surface. Because the density of milk foam is small and light, it is often chosen to increase the distance between the milk tank and the coffee liquid surface during fusion to avoid destroying the cleanliness and color of the oil.

(disintegration of milk foam structure instability caused by poor fusion)

In general, the size of the fused milk flow is a little smaller than that of the drawing stage, in order to ensure that the milk foam and coffee are fully fused without destroying the cleanliness and color of the oil.

If the injected milk is too coarse, it will produce a greater impulse, and it is easy to appear the phenomenon of turbulence, so it will generally choose a finer milk flow to carry on the fusion.

At the same time, the size of milk flow should be carried out as much as possible with the quality of milk bubbles. Thicker milk bubbles can be injected with higher distance and finer milk flow, while thinner milk bubbles can be fused with micro-coarse milk flow and closer milk flow.