1. The egg white is mixed with egg yolk. Egg yolks contain oil, and oil will seriously affect the beating of egg whites. Even if only a little egg yolk is mixed into the egg whites, the egg whites will not be able to be beaten, and new egg whites will have to be prepared.

2. The sugar added is not enough. When beating egg whites, you basically need to add fine sugar, because egg whites need sugar to maintain the stability of the protein structure.

3. There is oil and water in the whipping basin. The fat in the egg yolk will affect the beating of the egg white, and the oil and water will be more direct. Before sending, clean all the oil and water in the basin.