It always starts with the best of intentions – you hard boil a dozen eggs to take for lunch every day. But you forget a day or two, and soon you’ve got quite a few extra hard boiled eggs in your refrigerator. How long will they last, and do hard boiled eggs go bad?
Do hard boiled eggs go bad?
Hard boiled eggs do spoil, even under the best conditions. Surprisingly, the shelf life of hard boiled eggs is actually less than that of fresh eggs, as the process of boiling the eggs removes the protective coating on the shells. Egg shells are naturally porous, and without this coating, moisture and bacteria can enter the egg quite easily.
With the shells left on, hard boiled eggs can last up to seven days in the refrigerator. If the shells are removed after cooking, the shelf life of the eggs is reduced to just five days. Hard boiled eggs should always be refrigerated within two hours of cooking, and to be sure that the eggs stay in a safe temperature range, submerge them in ice water immediately after boiling.
Image used under Creative Commons from Andrew Toskin
Signs of Spoilage
Odor is really the best indicator of spoilage. If the egg smells at all like sulfur, or has any sort of rotten odor, it has likely spoiled and should be discarded.
While a greyish egg white and a green ring around the yolk may look unappealing, they do not indicate that a hard boiled egg has spoiled. Both of these flaws in appearance are the result of chemical reactions that occur when an egg is cooked for too long. While the eggs may not look as appetizing, and the texture may be a bit different than eggs that are cooked for slightly less time, they are still safe to eat.
If hard boiled eggs are still in their shells, you can check them for freshness with a glass of cold water. Drop the egg into the water. If the it sinks to the bottom, it is still good. If it begins to float a tiny bit, it is starting to spoil, and if the egg floats to the top, it has spoiled. This is because gas is lighter than water, and so any gas released from the egg spoiling will cause the egg to float. This trick also works with fresh eggs, and can be used to determine which ones to boil, and which to discard.
Storing Hard Boiled Eggs Long Term
While raw eggs can be frozen with few texture changes, this is not the case with hard boiled eggs. Cooked egg whites will become fairly rubbery after freezing, and so freezing whole hard boiled eggs is not recommended.
If you would like to freeze hard boiled eggs to use in egg salad, or similar applications, try grating the whole egg in a cheese grater, and mixing thoroughly. Do not add condiments or other ingredients to the egg mixture, and freeze in an airtight container for up to a month. Thaw the egg mixture in the refrigerator overnight before adding the other ingredients. The small size of the chopped egg pieces, combined with the other ingredients in an egg salad, will yield a much better texture than if the egg had been frozen whole.
Pickling hard boiled eggs, though it requires a bit of work, is another method for extending their shelf life beyond a week. Hard boiled eggs can be preserved for up to four months when pickled. To prevent bacteria growth, be sure to use a brining solution that is high in vinegar, and to keep pickled eggs in a sealed container in your refrigerator.