People in northern China, especially those in Beijing and Tianjin, like to eat jiaozi. Sex comes from the saying "at the time of sexual intercourse". Lunar New Year's Eve is the alternation of the old year and the new year, and beginning of winter is the turn of autumn and winter, so jiaozi can't help eating when he is having sex.

Speaking of beginning of winter eating jiaozi, it is said that Zhang Zhongjing, a famous doctor in the Eastern Han Dynasty, retired and went home in his later years. Seeing the cold weather, many people's ears were frozen, so he set up a big pot by the Yellow River, put mutton, peppers and herbs to dispel the cold, fished it out and chopped it up, wrapped it in an ear-like dough and cooked it in a pot. The shape is the same as the ear, and jiaozi is wrapped in these fillings.

Therefore, the old man who eats jiaozi in beginning of winter is also called "An Er", and there is even a saying that "beginning of winter messed up the jiaozi bowl, and no one cares whether his ears are frozen".

Nutritional components of jiaozi.

From the perspective of culinary science, the cooking method of cooking jiaozi with water (steam) as the medium only needs about 100, which can not only cook food, but also sterilize it, thus ensuring food safety. Moreover, the nutritional components of food will not be lost due to peroxidation or hydrolysis during cooking.

From the perspective of diet structure, jiaozi's fillings are all wrapped in dough, which can properly match grains, vegetables, fruits and meat, so that the main and non-staple foods are reasonably matched, rich in nutrition, balanced in acid and alkali, and the diet has a pagoda structure.

From the point of view of nutrition, jiaozi is famous for boiling, steaming and frying as heat transfer media, which can fully decompose starch polysaccharide in food, which is beneficial to human body's absorption and conforms to China people's eating habits.