White dew is an important solar term reflecting the cold growth in nature. On white dew day, people always have longan tonic. On this day, people gather "ten kinds of white" to stew silkie chicken. It is said that eating it can nourish the body and boost immunity. There are some areas that have the habit of eating sweet potato, because sweet potato has tonic deficiency, invigorating spleen appetizer, strong kidney Yin effect. Nanjing people are very fond of "white dew tea", people also like the tea they pick and the wine they make at this time.