Latte milk foam teaching skills of latte coffee milk foam smooth and long-lasting

(Oh, my God, today's show is great!) A minute or two later…the foam burst! There are "craters", and the flowers are not good... Why!

(The mental journey of the flower pulling partner)

Looking at the moon's surface like milk foam is really very uncomfortable, it's okay! This article on the front street will analyze the reasons for the disintegration phenomenon ~(quickly pick up the small notebook to remember the key points)

Composition of milk foam

The stability of milk foam is affected by the presence of casein colloidal particles in milk protein and whey protein casein colloidal particles, which makes the milk surface form tension. When steam hits the milk surface, a large number of bubbles of different sizes are formed, and then the position of the steam stick is adjusted to make the milk vortex "chop up" larger bubbles, thus obtaining fine milk foam like smooth surface.

(I am picture 2)

Causes of rapid foam collapse

- Milk to go-

1. Use refrigerated fresh milk: refrigerated fresh milk is rich in protein and cream, protein is the key to milk foam production, and cream is one of the main factors in stabilizing milk foam. This also explains why lattes made with skim milk break down faster.

2. Put steam before each milk foam: steam stick will have moisture condensed in the air outlet when it is stopped. If the moisture is not discharged before the milk foam is sent, the moisture will affect the difficulty of milk foam, and the natural decomposition speed of milk foam will become faster.

3. Milk temperature: general milk recommended temperature between 55-65℃, the highest does not exceed 70℃, too high temperature will lead to protein decomposition, milk foam stability will also decline, milk foam decomposition speed will also accelerate.

4. Excessive tapping of the milk tank after the milk foam is sent: After the milk foam is sent, there will be many small partners who have the habit of tapping the milk tank, the purpose is to shock the large bubbles on the surface. However, if you continue to tap the milk tank, it will speed up the dissipation of fine milk bubbles, and it will easily disintegrate after fusion with coffee. Therefore, it is not recommended to continue to shake the cylinder in front of the street. Generally, it can shake 2-3 times after the completion of the transmission. If there are still a lot of big bubbles after 2-3 vibrations, it is recommended to re-send the milk, because too many big bubbles pull flowers not only do not look good, after fusion, the surface of the milk bubble will quickly appear large "craters".

- Espresso-

1. Freshness of coffee beans: Too fresh coffee beans contain a lot of carbon dioxide. The extraction was carried out at 9Bar pressure and in a sealed condition, carbon dioxide and water were supersaturated. At the same time, the fat of the coffee is emulsified and then encapsulated with carbon dioxide and extracted with the coffee solution. After extraction, carbon dioxide in the oil will continue to return to the air. After fusion with milk, carbon dioxide emission speeds up the disintegration of milk foam.

2. Espresso extraction: extraction time is too short, espresso oil is too thin, milk and coffee fusion will appear when drifting; extraction time is too long, espresso oil is too thick, milk and coffee difficult to carry out uniform fusion. In both cases, milk and coffee blend unevenly, which is one of the reasons why milk bubbles are easy to disintegrate.

- Fusion-

As mentioned above, the degree of fusion of coffee and milk also affects the rate at which latte foam breaks down. Under normal circumstances, the higher the degree of fusion, the more stable the milk foam will be, and the decomposition speed will slow down. If the fusion is uneven and the coffee surface is rough, the milk foam will become unstable and decompose faster. The best blend of latte coffee is a uniform liquid color and a smooth surface. (See Figure 2 of this article)

(Milk and coffee blend unevenly)

To blend milk and coffee evenly, in addition to the fineness and thickness of the foam, the amount of water (nai) injected during fusion and the speed of the circle during fusion.

Generally, the flow of water (nai) will be a little thinner than the pattern stage, in order to allow the milk foam and coffee to fully blend without destroying the cleanliness and color of the oil. Too fast a loop injection will tend to hit large bubbles, too slow a loop injection will make it difficult for milk and coffee to fully fuse.

- Yeah! Useful knowledge points added-