It is believed that the milky white color of cream soup represents nutrition, but the truth is that the milky white color is simply an emulsification phenomenon where fat micro-drops are evenly distributed in water. When light encounters these tiny droplets, it scatters, creating the visual effect of a milky white color. Milk appears milky white for the very same reason. In fact, the fat in milk is pale yellow, as you can see from butter; but after emulsification, it forms a milky white color, such as in the case of light cream. The milky white color of fish soup, meat soup, duck frame soup, and pig's trotter soup is based on the exact same principle. As long as you have three components, you can form a "cream soup": fat micro-drops, an emulsifier, and water. In these soups, there are ingredients rich in fat. Under the action of boiling and churning, the fat forms micro-drops, which are enveloped by an emulsifier, creating a stable emulsion system that is evenly dispersed in the water. So, where does the emulsifier come from? It comes from the soluble proteins in the ingredients. Protein has certain emulsifying properties; it coats the outside of the fat droplets, allowing the fat, which is completely incompatible with water, to be evenly dispersed in water.
Understanding this, it becomes clear that whether a soup can be cooked into a cream soup has little to do with its nutritional value. However, having said that, making a cream soup does require some skill; that is, the operational process must fully meet the various conditions for forming an emulsion.
Key Points for Making Milky White Soup
To successfully make a cream soup, you need to provide ingredients rich in fat and ingredients rich in soluble protein. For example, crucian carp is an ingredient rich in soluble protein but low in fat. If you use only crucian carp to make soup, you won't get the cream soup effect. How can you supplement the fat in it? You need to pan-fry the fish in oil. The oil from frying the fish, when poured into boiling water, forms small droplets of fat. However, these droplets are still too large, and without an emulsifier to help them, as soon as the water calms down, they will clump together and fail to form a cream soup.
Therefore, you need to cook over medium heat to keep the soup constantly boiling, so that the small fat droplets are continuously broken up and cannot clump together; at the same time, during the cooking process, the soluble protein from the fish gradually dissolves out, coating the outside of the fat droplets, thus forming a cream soup. Once the milky white color has formed, you can continue to simmer it over low heat.
Therefore, the key points for making a cream soup are completely different from those for making a clear soup. A clear soup requires no added oil and no obvious boiling process; whereas to make a cream soup, you must have ingredients rich in fat, or add cooking oil externally, and you also need to maintain a boil. You can only add boiling water, not cold water.
If you want to make a cream soup simply, you can use just one simple ingredient: mayonnaise (a pale yellow or milky white salad dressing). Egg yolks are rich in lecithin, which is an excellent natural emulsifier. Salad dressings and mayonnaise are products made using the emulsifying properties of egg yolks. By adding mayonnaise to boiling water and stirring it well, you can easily get a milky white soup.
To control weight, one should drink cream soup less often
By this point, you can understand an important fact: cream soups are all soups containing a considerable amount of fat. Therefore, for people who are not deficient in fat and protein, drinking cream soup may not be nourishing, but it will definitely lead to a significant intake of fat.
When drinking soup with floating oil on top, people are usually very vigilant and often skim off the oil before drinking. However, when drinking cream soup, people are often complacent, not realizing that it contains a lot of fat, and because it tastes delicious, they think it is very nourishing and often drink several more bowls.
Therefore, it is necessary to remind people that if they want to control their weight, they should not often make cream soup, and they should also pay attention to controlling the amount when drinking it. In comparison, drinking clear soup is a safer option.