How to Tell If an Egg Has Gone Bad

The water test is a practical way to estimate an egg’s age. Place the egg in a bowl of water: if it sinks and lies flat on the bottom, it is fresh; if it stands upright near the surface, use it soon; if it floats on the surface, it is old and may have spoiled. Also check the smell and appearance after cracking it open. As an egg ages, it loses moisture and carbon dioxide through pores in the shell. This makes the air cell inside larger, so the egg becomes lighter and starts to float. The float test can therefore indicate age, but a floating egg is not necessarily spoiled. Crack it open and check its smell and appearance before deciding.

How Can You Tell If an Egg Has Spoiled?
A few simple checks are enough to assess an egg, and using them together gives a more reliable result:

• If a cracked egg has a sharp, sulfurous, or rotten smell, do not eat it.
• Noticeable cloudiness or a pinkish or greenish tint in the egg white can indicate spoilage.
• Discard an egg if its shell is cracked, moldy, or sticky.
• If it floats, check its smell and appearance carefully.

As with other perishable foods such as milk, the safest choice is not to eat an egg if you are unsure.

How Should You Store Eggs to Prevent Spoilage?
Proper storage helps eggs stay fresh longer. A few simple habits can help:

• Refrigerate eggs as soon as possible after purchase.
• Keep them in their original carton with the pointed end down.
• Store them on an interior refrigerator shelf, not in the door, where frequent opening and closing can cause temperature fluctuations.
• Eat prepared foods containing raw egg, such as homemade mayonnaise, promptly and keep them refrigerated.

Why Does an Egg Smell Different When It Spoils?
As an egg spoils, bacteria break down its proteins and release sulfur-containing compounds. These compounds cause the sharp, unpleasant smell associated with spoiled eggs. A stronger smell can indicate more advanced spoilage, but even a faint odor should be taken seriously; do not eat the egg.

What Are Common Mistakes When Checking Egg Freshness?
Some common mistakes can lead to a wrong assessment. Relying only on the expiration date and skipping the smell and appearance checks is one of them. Leaving eggs at room temperature for a long time can also increase the risk of spoilage. Use the water test together with a smell and appearance check. If you are unsure, do not eat the egg. This simple habit helps protect health and makes cooking with greater peace of mind easier.