fresh egg test
Eggshells are very porous and, over time, air passes through the shell into the egg. Its shelf life diminishes as more air enters the shell, which will also make it more buoyant. A simple way to test for freshness is to place the egg in a bowl of water. If the egg lays on its side at the bottom, it is still fresh. If the egg tilts at an angle or stands upright on the bottom, it should be eaten very soon or hard-boiled. If the egg floats to the top, it is past its prime and not good for eating.