Eco-Cycle recommends that whole eggs not be composted, although eggshells can be composted (eggshells are high in calcium and good for the soil). There are three reasons for this recommendation.
- Whole eggs tend to attract unwanted attention from animals such as mice, skunks, buzzards, and bears. Biting insects may also lay eggs in compost that contains whole eggs, leading to more flies and more bites.
- The bacteria that do most of the work in a compost pile are aerobic bacteria, which require oxygen to digest waste. These bacteria oxidize carbon compounds and generate heat as a by-product of their growth and reproduction. This heat accelerates the activity of other bacteria, speeding the breakdown of materials in a compost pile. In contrast, the bacteria that thrive on meat scraps and other high protein sources, such as eggs, are anaerobic. Anaerobic bacteria grow quickly without fresh air. They break down proteins to generate energy, but do not produce much heat.
- The by-products from the breakdown of eggs can make a compost pile stink.
While it is not recommend that whole eggs be composted in a typical compost pile, compost bins exist that have been specially designed to handle such materials. If you do compost whole raw eggs, it is best to crush them prior to adding them to the compost pile, or gas pressure will build up while they decompose, resulting in little explosions when the eggs are disturbed that can be very stinky. It will also be necessary to add more plant materials to help absorb the excess water contained in whole eggs. Overly wet compost will stink and will not allow air to travel through the composting media.