I once cracked an egg straight into a hot pan without checking it first. The smell hit me before the yolk did, and I nearly lost my breakfast along with my appetite for the rest of the day.
Quick answer
To tell if eggs are bad, do the float test (bad eggs float in water), check for a sulfur smell when cracked, and look for pink or black spots inside. Fresh eggs sink and lie flat, sit slightly upright, or stand on end depending on age — but they should never float.
Here’s the thing nobody tells you: that “sell by” date on the carton is basically a suggestion. Eggs can last weeks past it and still be perfectly fine, or they can go south early if they’ve been sitting in a warm car trunk. So instead of squinting at a date stamp, you need real tests you can actually trust. I’ve broken more bad eggs than I’d like to admit over the years, and I’ve picked up a handful of tricks that take seconds and never fail me.
The Float Test Is the Fastest Way to Check Freshness
Fill a bowl or glass with cold water and gently drop the egg in. If it sinks and lays flat on its side, it’s fresh — eat it whenever you want. If it sinks but stands upright at the bottom, it’s still good but a bit older, maybe two to three weeks in. If it floats to the top, toss it. Here’s why this works: eggshells are porous, and as an egg ages, air seeps in through thousands of tiny pores, forming a pocket at the wide end. That air pocket grows over time, and once it’s big enough, the egg becomes buoyant enough to float. It’s basic physics, not folklore, and it’s been reliable in my kitchen for over a decade.
A Sulfur Smell Means the Egg Is Definitely Bad
Crack the egg into a separate bowl before adding it to anything else, and give it a sniff. A fresh egg smells like almost nothing at all. A bad one smells like rotten eggs — sharp, sulfuric, and impossible to mistake for anything else. This is your most reliable test because smell doesn’t lie the way appearance sometimes can. I learned this the hard way during a baking marathon for a friend’s birthday cake: one egg out of six reeked the second it hit the bowl, and I’m grateful I cracked each one separately instead of dumping all six into the batter at once.
Visual Clues Inside the Egg Can Reveal Spoilage Too
Look at the egg white and yolk once it’s cracked open. Pink, green, or iridescent whites usually signal bacterial contamination, most commonly from Pseudomonas bacteria. Black spots inside the shell or on the yolk point to mold growth, which can happen if moisture got trapped during storage. A cloudy white, on the other hand, is actually a good sign — it means the egg is very fresh and still has high levels of dissolved carbon dioxide.
That last point surprises almost everyone I mention it to. Most people assume cloudy equals old or gross, when it’s the opposite. Clear, runny whites are the ones that tell you an egg has been sitting around for a while, since the carbon dioxide has had time to escape through the shell.
The Shake Test Can Catch What Your Eyes Miss
Hold the egg up to your ear and give it a gentle shake. A fresh egg makes almost no sound because the contents are firm and fill the shell snugly. An old egg sloshes audibly, since the white and yolk have thinned out and there’s more room for them to move around inside. It’s not as scientifically airtight as the float test, but it’s a quick first-pass check I use when I’m grabbing eggs from the back of the fridge and don’t want to dirty a bowl.
Checking the Carton Date Still Matters, Just Not as Much as You’d Think
In the US, eggs are safe to eat for 3 to 5 weeks after the pack date, even if the “sell by” or “best by” date on the carton has already passed. That date is about peak quality, not safety. I know that sounds counterintuitive if you’ve spent your whole life trusting expiration labels blindly, but the USDA itself confirms eggs stored properly at 40°F or below stay safe well past that printed date.
Here’s a quick rundown of storage practices that actually extend shelf life:
- Keep eggs in the coldest part of your fridge, not the door, where temperature fluctuates every time you open it
- Store them in the original carton so they don’t absorb odors from onions or garlic sitting nearby
- Avoid washing eggs before storing, since it strips the protective bloom coating that keeps bacteria out
- Never leave eggs out at room temperature for more than 2 hours
What to Do If You Suspect an Egg Is Bad: Practical Action Steps
If you’ve cracked an egg and you’re still not 100% sure, follow this sequence rather than guessing:
- Crack it into a separate bowl first, never directly into your mixing bowl or pan.
- Smell it immediately — trust your nose over your eyes.
- Check the color and texture of the white and yolk for pink, green, or black discoloration.
- If it passed the float test earlier but smells off now, throw it out anyway. Smell always overrules every other test.
- When in doubt, throw it out. A single egg costs far less than a bout of food poisoning.
I keep a little laminated card taped inside my pantry door with these five steps, honestly, because I used to forget the order when I was half-asleep making Sunday breakfast. Now it’s muscle memory, and I haven’t tossed a good egg by mistake or eaten a bad one since.
FAQs
How do I tell if eggs are bad without cracking them?
The float test is your best bet without cracking the shell. Fill a bowl with cold water, drop the egg in, and watch whether it sinks, stands upright, or floats. A floating egg should go straight in the trash.
Can you eat eggs a month after the expiration date?
Sometimes, yes, as long as they’ve been refrigerated consistently and pass the float and smell tests. Eggs are typically safe for 3 to 5 weeks past the pack date, though quality does decline over time.
Does a cracked shell mean an egg has gone bad?
Not necessarily, but a cracked shell does raise the risk of bacterial contamination, since it removes the protective barrier. If you notice a crack, use that egg soon and cook it thoroughly rather than eating it raw or undercooked.
Why do some fresh eggs smell a little different straight from the carton?
That faint smell is usually just the natural coating or slight moisture on the shell, not spoilage. Once you crack it open and there’s no sulfur odor, it’s almost certainly fine to use.
Is it safe to eat an egg that stood upright in the float test?
Yes, an egg standing upright in water is still safe to eat, it’s just a few weeks older than a fresh one. Only floating eggs should be discarded.
Conclusion
Bad eggs aren’t something you have to guess about anymore. Between the float test, a quick sniff, and a glance at the color once it’s cracked, you’ll know within seconds whether that egg belongs in your omelet or your trash can. These habits take almost no extra time, and they’ve saved my breakfasts more times than I can count.
Have you ever cracked open a rotten egg by accident? Drop your story in the comments — I’d love to hear how bad it really was.
