In the process of boiling milk, a thin film forms on its surface. It can be the same color as the milk itself, or with a yellowish bubble bloom in the case of increased fat content.
Milk foam
To put it simply, foam is just fat. Although, in fact, its composition is a little more complicated. It includes fats, minerals and milk proteins - casein, albumin and globulin. Most of all casein (about 82% of the total share of all proteins), slightly less albumin (12%) and globulin (6%).
Despite the fact that the foam is most often removed from milk before it is ingested, there is nothing harmful in it. It's just that its consistency becomes stronger as the milk cools and it becomes difficult to swallow it whole.
A distinction should be made between the froth that whole milk gives when standing (fats mainly accumulate there) and the froth that is formed when the milk is boiled.
Foam forms during boiling when the temperature reaches approx. 50 ° C. Under the influence of temperature, milk protein begins to change its qualities, hence the foam appears.
Another reason why they try to get rid of the foam as soon as possible, even at the moment of boiling, is that it does not allow air to pass through, completely covering the surface of the milk. The foam is immediately removed, because when it boils, the air rising from the bottom of the pan does not find a way out. This is how milk "runs away", which no housewife will ever be happy about.
How does the foam form?
If you focus on the chemistry of the processes that create froth in milk, they look like this. During boiling, proteins, primarily albumin, begin to fold. Minerals such as calcium and phosphorus are converted into insoluble compounds.
Milk fat envelops all the resulting solid inclusions and a whole film is obtained, which can be removed from the surface of the milk with a wooden stick in a whole layer. In cooking, there are tips for drying such a foam (or freezing). When it is dry, it is cut into small pieces and served.
The thickness of the froth depends on the fat content of the milk. Whole milk has the most of it, while store-bought (skim) milk practically does not foam.
There are cases when the foam can be harmful: cause headache, nausea, skin rashes and itching, intestinal and stomach upsets. The reason may be a lack of lactose, an enzyme that breaks down milk sugar in the body. Or individual sensitivity to milk proteins.
If the child does not want to drink milk because of the froth, then it is better to remove it before the glass of milk falls on the dining table. You can replace boiled milk with other dairy products (kefir, yogurt, cottage cheese desserts, etc.). If, on the contrary, the child loves foam, then it is more convenient to remove it from the surface of the milk, using straws.
