If the egg recently cracked (when removing it from the fridge or on the way home from the grocery store), use it right away. Otherwise, bacteria can enter through the crack and contaminate the egg. Hard boiling is one way to use the eggs. You can hard boil cracked eggs. However, the egg white will start to escape the shell during boiling. White strings will end up in the water, clouding the water. The boiled and peeled egg will be misshapen. This only means not to use these eggs in any showy dish, like deviled eggs. However, pasta salad, potato salad, or grain bowls are ideal for misshapen boiled eggs.