Americans refrigerate eggs because of US federal food safety regulations that require chicken eggs to be washed prior to sale. The process of washing eggs actually exposes them to bacteria because it destroys the outermost protective coating of the shell that keeps bacteria and other microorganisms from penetrating it. Refrigerating the eggs after washing helps prevent microorganisms from reaching within the porous shell. Egg refrigeration is not common in other countries, with the exception of Japan and Scandinavia, because of differing food safety standards that do not require washing beforehand. Instead, hens are required to be vaccinated against illnesses prior to laying eggs.
More about eggs:
- The US produces around 75 billion eggs each year, accounting for 10% of the total world egg supply.
- A hen lays an average of 250 eggs annually and most eggs are laid between 7:00 a.m. and 11:00 a.m. due to computer-controlled lighting in henhouses that stimulates egg production.
- The shell comprises approximately 9 to 12% of the weight of an average egg, and each shell contains up to 17,000 tiny holes.