Preserved eggs, also called preserved eggs and preserved eggs, are cooked by burying chicken and duck eggs in lime (quicklime) paste and generating heat through chemical reaction. Lime plaster contains soda (sodium carbonate), quicklime, plumbum preparatium powder, salt, black tea powder, lead oxide, cypress branches, etc.

Preserved eggs are not artificial eggs. Preserved eggs have a long history in China.

Eating preserved eggs is cool to relieve summer heat, but it is not advisable to eat too much at a time, especially for people with poor gastrointestinal digestion. Preserved eggs are easy to be contaminated by salmonella during curing. Once their shells are broken, or there are trachoma on the shells, or the eggs themselves are of poor quality. In addition, lead is harmful to human body, and it is prone to poisoning symptoms such as fever, abdominal pain and diarrhea, nausea and vomiting after eating, but it is often eaten.