[header] How to cook hard boiled eggs without cracking [title] Bring your eggs to room temperature before cooking. [step] If you keep your eggs in the refrigerator, it's important that you don't try to cook them cold. Eggs crack because gases heat and expand within the shell.
When the pressure becomes too great, the gases escape by cracking weak points in the porous shell. Bringing eggs to room temperature before cooking slows down that process.