It’s Chinese New Year, how to cook a perfect plate of dumplings?

What are the must-eat foods during the Spring Festival? Dumplings must be on the list!

Dumplings originated from ancient Chinese jiaozi , originally named "jiao'er" , a traditional Han Chinese noodle food with a history of more than 1,800 years. Eating "dumplings" on New Year's Eve is a feast that cannot be replaced by any delicacies from land and sea. Making dumplings delicious is the most important thing.

First, let's define what is considered well-cooked. Dumplings are generally divided into two parts, the stuffing inside and the dumpling skin outside . When the stuffing and the skin of the dumplings are cooked, and the rubber is not broken, it is considered well-cooked.

There are many types of fillings, but the dumpling skin is relatively simple, which is flour , generally medium-gluten flour, that is, the protein content is about 11% and the starch content is more than 60%. The dumpling skin made with this kind of flour is soft and chewy.

Before cooking dumplings, let’s first introduce our protagonist, starch .

Thousands of glucose molecules linked together form starch. If the glucose is arranged in a straight line, it is called amylose . If the glucose is arranged like branches, it is called amylopectin .

When we usually say that the dumpling skin is cooked, we are referring to the gelatinization process of starch .

Starch is insoluble in cold water, but when starch is heated to a certain temperature with excess water, its particles absorb water and swell, and the fluidity of the molecules increases, causing the starch molecules to lose rigidity and gain flexibility . At the same time, during the gelatinization process, the double helix structure of amylose opens and detaches from the particles, existing in the starch paste system as an amorphous structure , while amylopectin is fully expanded or even ruptured, forming starch paste. It's like a neatly arranged team that was suddenly broken up.

Generally speaking, dumpling skin is easier to cook than filling, which requires the so-called "three ups and three downs" operation.

"Three ups and three downs" refers to the process of adding cold water to boil the water again after it boils during the process of cooking dumplings. Some people may have questions here, why can't the water be boiled? This is related to the gelatinization process mentioned above. In layman's terms, if the water keeps boiling, the dumpling skin will keep gelatinizing and expanding, and it will easily break in a short period of time, but the stuffing inside is not cooked due to insufficient cooking time. At this time, adding some cold water can effectively shrink the dumpling skin, prevent the dumpling skin from being broken, and make the dumpling skin more chewy.

You can also open the lid of the pot or turn down the heat to achieve the same effect. In addition, you can also add salt, because sodium chloride can increase the gelatinization temperature of gorgon starch . When the gelatinization temperature rises, the dumpling skin will not be so easy to cook. In addition to adding salt, sucrose and sodium carbonate** (soda)** will also increase the gelatinization temperature of starch. However, the addition of the above items will affect the taste, and this step varies from person to person.

Now that we have introduced the dumpling wrappers, there are many types of fillings. The fillings can be beef mixed with green onions, pork mixed with pickled cabbage, mutton mixed with carrots, leeks and vermicelli mixed with eggs, etc. You can choose any filling you want. Different fillings take different amounts of time to cook, so you need experience.

Making dumplings is about custom, happiness, and simple philosophy. The whole family sits happily at the table, working together, and the children always use their imagination to make the dumpling skins into various creative shapes. Making dumplings is a beautiful thing.

Creative team: China Science and Technology Museum New Media Team

Review expert: Sun Yafei, Ph.D. in Chemistry, Tsinghua University

This article comes from: China Digital Science and Technology Museum