First of all, bird's nest is saliva secreted by Jin Siyan. This is because their nesting place is in a cave by the sea. There is nothing here, so they build their nests by spitting. The main components of this saliva are protein and essential amino acids for human body. People who collect bird's nest will do a preliminary treatment when they come back, mainly to clean up the bird's nest feathers and other debris, maintain a perfect appearance and sell well.

In the hands of consumers, it is necessary to clean the bird's nest, remove impurities and dirt, and leave the clean bird's nest for stew.

So the bird's nest is quite clean and hygienic.