2. The surface of the dumplings taken out of the refrigerator is frozen hard, so it can't be directly heated with cold water. Put cold water in the pot and heat it in advance. When the water boils, add the dumplings to prevent them from sticking together and breaking. When the glutinous rice balls float and cannot be fished out immediately, add cold water once and continue to heat them, and then they can be fished out and eaten.