Many people routinely wash eggs before refrigerating them. According to experts, however, eggs do not need to be washed and, in fact, washing may remove the protective layer on the outside of an egg or even promote the growth of bacteria. If eggs need to be cleaned, it is recommended you wipe them with a soft, dry cloth.
The Council of Agriculture’s poultry farming section chief Lee Yi-chien says eggs that have been washed and packaged do not need to be washed again, while unpackaged eggs that have not been washed can remain fresh for up to a month because of their natural protective coating. In other words, washing unwashed eggs would only remove their natural protective layer, thereby shortening their shelf life.
Chen Ming-ju, a professor at National Taiwan University’s Department of Animal Science and Technology, says that if eggs are placed in the refrigerator immediately after they have been washed, the moisture could promote bacteria growth. According to Chen, chicken droppings and dirt that attach to eggs often contain salmonella, which can survive in the refrigerator if the temperature is above 4 degrees Celsius. If eggs containing salmonella are placed next to leftovers or other food in the fridge without any protection, there is a high chance of salmonella infection.