To make soup, Cantonese people first use some protein-rich animal ingredients, such as ribs and ribs of pigs, cattle and sheep, or chickens and ducks with bones, as well as some aquatic products. Coupled with some plant raw materials and spices that are both food and medicine, after a long period of slow simmering, you will finally get a soup that is thick white in color, fibrous in taste, and viscous in texture.

The "rich white color" comes from fat. There is rich fat in the bones and meat, which is boiled until it keeps rolling in the soup, and is dispersed into small milk droplets by the protein, which looks white like milk. The longer it is cooked and the more bones it has, the thicker the emulsion will be and the whiter it will look.

“Delicious taste” is the most attractive thing about making soup. There are some fat-soluble aroma substances in the ingredients, which will enter the soup along with the fat. There are some free amino acids in meat and bones. During long-term high-temperature stewing, some proteins are hydrolyzed and some amino acids are also released. There are some free amino acids that have an umami flavor, such as glutamic acid, which is the chemical component of MSG.

Bones and other soup ingredients (such as mushrooms) also contain relatively large amounts of inosinic acid and guanylic acid, which will also run into the soup during the stewing process. Although these nucleotides produce limited umami flavor on their own, they can "synergize" with glutamic acid to increase the umami flavor several times.

In addition, some free amino acids can react with sugar in the soup to generate flavor substances. The combination of these flavor substances from different sources brings a rich umami flavor to the soup. The longer you simmer, the more of these ingredients will enter the soup and the more delicious the soup will taste.

The "sticky texture" comes from collagen. There is a certain amount of collagen in meat, and it is extremely rich in bones and skin. Collagen has a large molecular weight and dissolves into water at high temperatures. The colloidal particles they form can also scatter light and appear white. As the temperature of the soup drops, it becomes thicker. If the concentration of collagen in the soup is high enough, cross-linking will occur between them after cooling, fixing the water molecules and other components in the soup, and the solid formed is "skin jelly".