Whether an egg has spoiled can be told most practically with the water test: if an egg sinks to the bottom of a bowl of water lying flat, it's fresh; if it stands upright while staying close to the surface, it should be eaten soon; if it floats entirely on the surface of the water, it has likely spoiled. The answer to how to tell if an egg is spoiled is clarified not only by the water test, but also by the smell and appearance that come up when the shell is cracked.
Over time, an egg loses moisture and carbon dioxide through the pores in its shell; as this loss increases, the air pocket inside the egg grows larger, making the egg lighter in water and causing it to start floating. This is why the water test is a reliable method that indirectly shows the egg's age. However, not every floating egg is necessarily spoiled; for a definitive decision, the shell should be cracked and the smell and appearance should also be checked.
How Can You Tell an Egg Has Spoiled?
A few simple checks are enough to tell whether an egg has spoiled. The result is much more reliable when these checks are applied together.
- If a sharp, sulfurous, or rotten smell is detected when the egg is cracked into a bowl, it should definitely not be eaten.
- Noticeable cloudiness, or a pinkish or greenish tint, in the color of the egg white is a sign of spoilage.
- If cracks, mold, or a sticky texture are noticed on the surface of the shell, the egg should be discarded.
- If the egg floats completely in the water test, caution is warranted, and a smell and appearance check should definitely be done.
- As with other quickly perishable products like milk, not eating an egg in a doubtful situation is the safest choice.
How Should Eggs Be Stored to Prevent Spoilage?
Keeping an egg fresh for a long time depends on the right storage conditions. A few simple habits can noticeably extend this period.
- Eggs should be put in the refrigerator as soon as possible after purchase.
- Eggs should be stored in their original carton with the pointed end facing down.
- Eggs should be stored on interior shelves, not in the refrigerator door; the door area is more exposed to temperature fluctuation due to being opened and closed frequently.
- Prepared dishes containing raw egg, such as homemade mayonnaise, should be consumed quickly and kept refrigerated.
Why Does an Egg Smell Different When It Spoils?
When an egg begins to spoil, the proteins inside it are broken down by bacteria, and sulfur-containing compounds are released in the process. These compounds are the main source of the sharp, unpleasant smell characteristic of a spoiled egg. The more pronounced the smell, the more advanced the spoilage is expected to be; even a faint smell should be taken seriously and the egg should not be eaten.
What Are Common Mistakes Made When Assessing Egg Freshness?
Some mistakes when assessing egg freshness can lead to wrong conclusions. Looking only at the expiration date and skipping the smell and appearance check is chief among these mistakes. Leaving the egg at room temperature for a long time is also a factor, often overlooked, that increases the risk of spoilage.
The answer to how to tell if an egg is spoiled is applying the water test together with a smell and appearance check. Not eating an egg in a doubtful situation is the correct and simplest approach from a food safety standpoint. This small habit protects health in the kitchen and noticeably and lastingly makes preparing food with peace of mind easier.