When you drop a cold egg straight from the fridge into boiling water, the sudden temperature change, or ‘thermal shock’, can cause the shell to crack. They also break if they bump against each other in the pot.
The Ice Cube Hack: Before boiling, just place the eggs in a bowl of ice-cold water for 3 to 5 minutes. This simple step helps the egg’s temperature adjust slowly, reducing the risk of cracking. After this, put the eggs in a pot with cool water and then bring it to a boil.