A hen coats each eggshell with a protective layer of fast-drying liquid known as the bloom or cuticle. The bloom’s primary purpose is to protect a potential embryo from contamination so it can develop into a chick. If the bloom is washed off, bacteria can more easily penetrate the porous shell, compromising the egg’s contents, and the embryo’s development. If an egg is intended for use in the kitchen the contents of the eggshell benefit to some degree from an intact bloom. But the bloom is not made of Teflon and will degrade over time. The older an egg, the more time bacteria has to work its way in through eggshell pores. Generally speaking, the warmer the environment, the faster bacteria can grow.