Learn how to tell if an egg has gone bad using three simple tests. Discover what the float test really tells you, how to check an egg’s freshness, and what “expired” actually means.
How to Tell If an Egg Has Gone Bad — 3 Simple Tests Plus What “Expired” Really Means
Eggs can stay fresh for quite a while when stored properly, but it is not always obvious whether an egg is still good to eat. The date printed on the carton can be useful, but it does not necessarily mean the egg becomes unsafe the following day.
Fortunately, there are a few easy ways to check an egg before using it.
1. The Float Test
The classic water test is one of the easiest ways to check an egg’s age.
Place the egg gently in a bowl or glass of cold water.
- It sinks and lies flat: The egg is relatively fresh.
- It sinks but stands upright: The egg is older but may still be usable.
- It floats: The egg has become quite old.
Why does this happen? As an egg ages, moisture and gases gradually move through its porous shell. The air pocket inside becomes larger, making the egg more buoyant.
However, there is an important catch: the float test tells you more about an egg’s age than whether it is definitely safe to eat. A floating egg should be inspected carefully rather than automatically considered spoiled.
2. Crack It Into a Separate Bowl
This is one of the most useful checks.
Instead of cracking an older egg directly into your recipe, break it into a clean bowl first.
Look for:
- An unusual or unpleasant smell
- Pink, green, black, or otherwise abnormal discoloration
- Mold
- A strange or unusual appearance
A fresh egg generally has a mild smell. A strong rotten or sulfur-like odor is a clear reason to discard it.
If the egg smells bad after cracking, don’t taste it to see whether it is safe.
3. Check the Appearance and Texture
Once cracked, examine both the white and the yolk.
As eggs age, the egg white can become thinner and more watery, while the yolk may become less firm. These changes can indicate that the egg is older, but they don’t necessarily mean it has spoiled.
What is more concerning is an obviously abnormal color, mold, or an unmistakably foul odor.
When in doubt, throw the egg away. The cost of one egg is much lower than the risk of eating spoiled food.
What Does “Expired” Actually Mean?
This is where egg labels can be confusing.
Depending on where you live, egg cartons may display dates such as “sell by,” “best before,” or “use by.” These terms do not all mean the same thing.
A quality-related date generally indicates how long the producer expects the eggs to maintain their best quality. It doesn’t necessarily mean the egg instantly becomes unsafe once that date passes.
Food-safety guidance can also vary by country, so the safest approach is to follow the storage and labeling rules applicable where you live.
How to Store Eggs Properly
Proper storage makes a major difference.
Keep eggs refrigerated at a consistent temperature and avoid leaving them at room temperature for extended periods. Store them in their original carton when possible, which helps protect them and makes the date easier to track.
Also, don’t rely on smell alone for every food-safety decision. Some harmful bacteria may not noticeably change an egg’s smell, appearance, or taste.
The Bottom Line
The float test, smell test, and visual inspection are useful ways to evaluate an egg, but none of them can guarantee that an egg is free from harmful bacteria.
If an egg is cracked and smells rotten, looks abnormal, or you’re simply unsure about its safety, the safest choice is to discard it.
And remember: an egg being past a printed quality date does not automatically mean it has suddenly “gone bad.” Storage conditions, labeling rules, and the egg’s actual condition all matter.