How long is the foam suitable for making latte coffee? How thick is the foam?

The knowledge of getting rid of foam has also been shared in detail before Qianjie. Recently, however, a friend sent some videos of bubbling and asked Qianjie to give some suggestions. It just so happens that these problems are relatively easy for beginners to foam, so let's talk about a few points that should be paid attention to.

In the first category, the main reason for not having milk foam after beating is that the steam stick was buried too deep in the milk at the beginning. First of all, let's briefly understand how the steam stick sends out milk bubbles. The steam stick emits hot water vapor, which is sprayed directly into the milk and will only play the role of heating the milk. If the water vapor passes through the air and then enters the milk, it will send out milk bubbles, and when the air is pumped into the milk, there will be the sound of tearing the air, that is, the sound of "nourishing", so if there is a "nourishing" sound, just listen for the sound of "nourishing". Milk bubbles are essentially proteins that wrap around the air.

So if you want to get rid of milk bubbles, the steam holes must not be flooded with milk. But if all the steam holes are exposed, there are uncontrollable risks, such as sending out thick and rough milk bubbles quickly, or the steam is too strong to spray milk directly out of the vat. So generally the safest foam is the steam stick half-buried in the milk, if it is a porous design, you only need to ensure that a hole will not be flooded by milk. Second, the foam is very rough as long as the steam stick is not buried too deep, it can send out the foam, but it takes a lot of skill to make it delicate after sending it out. Before Qianjie, I was teaching everyone to get rid of the foam first and then to beat the foam. In fact, the two steps of sending and sleeping can be carried out at the same time, which is not so much pressure on the back.

The most important point of making love is to create a whirlpool. The water vapor emitted from the steam hole can not only pump the air into the milk, but also constantly cut the air wrapped in protein. We know that the more air the protein is wrapped in, the bigger the foam is and the easier it is to burst. And the water vapor can be used to break those unstable large bubbles and divide them into countless small bubbles, which have high stability and are not easy to burst. When many small bubbles are formed together, a layer of delicate milk bubbles is formed, and the purpose of creating a whirlpool is to control the water vapor from running around and concentrate on eliminating the big milk bubbles.

There are two main points to pay attention to in creating a whirlpool. The first point is the position and angle of the steam rod. When the steam rod touches the milk surface, it should be at 3 o'clock or 9 o'clock. It is best to form an angle of 60 degrees between the steam rod and the liquid surface, because if you want to create a vortex, you must have a horizontal force.

As long as you master the angle and position to create a whirlpool, you can make delicate milk bubbles even if you don't need hands.

The second point is to make a larger liquid surface as much as possible, the larger the liquid surface. In the case of a certain amount of milk foam, the larger the liquid surface, the thinner the milk foam layer. This is easy to understand. Another effect is that the large liquid surface is more likely to form a whirlpool. So you will see that some baristas will tilt the milk tank when they dispose of the foam in order to better form a whirlpool. However, this is not necessary, if you have the conditions, you can first use water to practice making a whirlpool, change more angles, and find the location of the whirlpool, which is basically not far from the end of the delicate foam. After learning to create a whirlpool, we come to the next step. In front of the street, I saw that some friends would create a whirlpool, but the milk foam was still very rough. The reason is that the whirlpool it creates is under the layer of milk foam, that is, the undercurrent. When we are making love, we have to move the steam hole to the foam layer in order to play a role. A friend will reflect, "if I move up a little bit, there will be a sound of nourishment, and the milk foam will increase again." This means that the angle of your steam rod is too small and it is not recommended to be less than 45 degrees. At the same time, the principle of masturbation is also very simple, that is, at the beginning, all the steam holes are buried, and then the milk tank is moved down little by little after creating a whirlpool. When the milk tank is moved down, the milk liquid level also goes down relative to the steam hole. When the steam hole shows the liquid surface, it will dispel the foam. The essence is to move a little bit, which can well control the amount of milk foam. And because the steam has been creating a whirlpool in the milk foam layer, the milk foam is in a relatively delicate state at the very beginning. When the right amount of milk foam is made, the milk tank is fixed and the milk tank can be made loose all the time. In order to achieve this stably, it is necessary to master the use of a milk tank to jam the steam stick to form a stable structure that can move up and down. In general, Qianjie suggests using the cylinder nozzle to jam the steam stick. When dispelling the foam, you only need to use the cylinder nozzle to move down the steam stick slowly. You can use clear water to practice, as long as you practice a few times, you will feel it.