Many people worry about the safety of cracked eggs, and rightly so. A cracked shell allows contaminants to enter the egg posing a risk to your health. Eggs that are cracked when you purchase them, or cracked before you gather them, should be discarded as there is no way to know if they are safe. However, there are some instances when boiling a cracked egg may be safe.
If you crack an egg when you are removing it from the refrigerator or preparing it for boiling, you can safely boil and eat the egg -- provided the egg was clean and sanitized before handling. Light cracks that do not break through the entire shell will not affect the egg.
Cracking While Boiling
Some eggshells crack when the egg is dropped into the pan of water. There is no need to discard the egg because of a crack. You can safely continue to boil and eat eggs that crack during boiling.
Appearance and Usability of Cracked Eggs
Some cracked eggs are safe to boil and eat but may not be suitable for serving whole or in preparations like deviled eggs that rely on symmetrical eggs for a pretty presentation. The whites of cracked eggs will protrude through the shell while boiling, creating a bulging mass of egg white. When peeled the egg will appear lopsided and misshapen. If the eggs are used for mashing, or in recipes like egg salad, the physical appearance of the boiled egg is not a concern. However, they may lack flavor and taste watery due to water seeping into the shell during boiling.
Eggs sold commercially have been sanitized and coated with oil to prevent bacteria and should not be washed at home. Washing fresh eggs may remove the protective oil and make your eggs more susceptible to harmful bacteria or other contaminants. Fresh eggs should not be left at room temperature for more than two hours. Because some eggs naturally contain salmonella, they should be cooked thoroughly before eating. Fresh eggs can be stored in the shell under refrigeration for three to five weeks, while boiled eggs can be stored in the refrigerator for up to one week.