Expired eggs often emit a foul smell and should not be eaten, as they may have lost their nutritional value and could taste unpleasant. If the egg smells normal, you can still use it, perhaps by quickly making an omelette or other dish. Your eyes can also help you assess whether an egg is still good. Examine the shell carefully—if it appears powdery, sticky, cracked, or damaged, it could indicate mold.
Additionally, when you crack the egg into a bowl, any strange discoloration in the egg white or yolk—such as blue, pink, black, or green—may signal that the egg has gone bad. If you are still unsure, simply fill a bowl with cold tap water and gently place the eggs in it. Fresh eggs will sink to the bottom and lay flat on one side. If an egg floats, it means it has gone bad due to the large air cell that forms at the base as the egg ages. Any eggs that float should be discarded