Welcome to the The Incredible Edible Egg™ Eggcyclopedia, where you can access the latest egg information from A-Z. The Eggcyclopedia was developed by the American Egg Board (AEB) on behalf of America's egg farmers who are committed to caring for their hens and producing high-quality eggs for you and your families.

Just click on any letter below to bring up a list of egg terms and their related definitions.


Shell Membranes:

Just inside the shell are two shell membranes, inner and outer. After the egg is laid and begins to cool, at the large end of the egg, an air cell forms between these two membranes.


Vitelline Membrane:

The strength of this yolk covering protects the yolk from breaking. The vitelline membrane is weakest at the germinal disc and tends to become more fragile as the egg ages.

– See Air Cell, Composition, Formation, Germinal Disc, Grading