Bloom

Also known as the cuticle, bloom is the coating or covering on the eggshell that seals the eggshell pores. The bloom helps to prevent bacteria from getting inside the shell and reduces moisture loss from the egg. In nature, the bloom dries and flakes off. Before they are sent to market, eggs are washed and sanitized, removing the bloom. About 10% of egg packers give eggs a light coating of edible mineral oil to restore the bloom.

– See Oiling