Why do eggs become lighter after being stored for a long time

Eggs stored for too long will become lighter, mainly due to factors such as water evaporation, carbon dioxide loss, and protein breakdown inside the eggs. Egg shells have breathability, and long-term storage can lead to gradual loss of internal substances. The surface of the egg shell has thousands of tiny pores that allow for gas exchange. Fresh eggs contain a large amount of water and dissolved carbon dioxide inside. As they are stored for a longer period of time, the water will continue to evaporate through the pores. At the same time, carbon dioxide inside the egg will also diffuse outward through the pores, and the loss of these two substances directly leads to a reduction in the weight of the egg. The higher the temperature and lower the humidity of the storage environment, the faster this substance is lost. Egg protein undergoes slow decomposition during storage, producing volatile substances such as ammonia. These gases will also escape through the pores of the eggshell, further causing a decrease in weight. If eggs are stored for more than a month, the yolk membrane will gradually become thinner, and the moisture in the yolk will also penetrate into the egg white area and evaporate. The continuous transfer and loss of internal substances result in a continuous decrease in the overall weight of the egg.

It is recommended to store eggs in the refrigerator compartment at a temperature of around 4 degrees Celsius, which can effectively slow down the rate of moisture and gas loss. When purchasing, pay attention to choosing fresh eggs and observe whether the eggshells are intact and free of cracks. Keep the eggshells dry during storage and avoid storing them together with other strongly scented foods. Regularly check the freshness of eggs, which can be determined by a float test. Fresh eggs will sink to the bottom of the water, while eggs stored for too long will float due to an enlarged air chamber.