Before cooking an egg, how do you find out if it is fresh or stale?

Immerse the egg in a bowl of water. If the egg lies horizontally on the bottom of the vessel containing the water the egg is probably fresh; if the egg stands on its pointed end, the egg may be several days old.

What is the basis for testing of freshness of eggs in this way?

Eggs contain tiny pores invisible to the naked eye, through which air can enter or leave the egg. The air in the egg is contained in the air cell situated at the broader end of the egg.

Due to the gradual evaporation of water from the egg after it has been laid, the air cell becomes larger as the days pass. This makes the broader end lighter than the rest of the egg, so if an egg that is several days old is placed in water, the broader side will float upward causing the egg to stand on its pointed end.


Picture Credit : Google