How to Tell If Eggs Are Bad: 6 Freshness Tests That Actually Work

So, you pulled out a carton of eggs from the back of the fridge and wondered, "Are these eggs still good?" We’re sure this scenario is common to many. 

Here's something worth knowing:  

The CDC estimates around 1.35 million Salmonella infections occur in the U.S. every year, and eggs are one of the most common sources.1 

That doesn't mean you need to panic every time you crack one open. It just means a quick freshness check, which takes just 30 seconds, is always worth it. 

In this blog, we'll walk you through six easy and reliable egg freshness tests you can do right at home. You'll also find out what bad eggs look, smell, and feel like, how long eggs last, what happens if you eat a bad one, and how to store them so they stay fresh longer. 

How to Read and Understand Egg Expiration Labels?

Before you run any test, it helps to understand what the dates on the carton actually mean. 

You may see a few different date labels on egg cartons, like: Best By, Use By, or Sell By. These dates can be confusing for you, but here’s what you should know; they don’t mean the eggs are instantly bad after that day.  

According to the USDA, eggs are safe to eat for three to five weeks from the Julian pack date, as long as they're properly refrigerated. That's often longer than the "Best By" date suggests. So, if you find a carton without a clear expiration date, look for those three digits. 

Still, dates alone aren't foolproof. The tests below will tell you far more than any printed number. 

IMPORTANT NOTE: Never taste an egg to test freshness. If anything looks or smells off, discard the egg immediately. Clean any surfaces or utensils it touched to prevent cross-contamination. 

What Are the Most Reliable Egg Freshness Tests? 

Test 1: Shell & Visual Inspection [The First Check] 

What To Do? 

Pick up the egg and take a close look at the shell before anything else. Check for any cracks or unusual discoloration. 

What You May See: 

One more thing to check: If you're in a darkened room, shine your phone's torch briefly on the shell. Hidden hairline cracks become visible under light, cracks the eye might miss in normal lighting. (More on this in Test 5.) 

Note: A cracked egg you just discovered can still be cooked and eaten right away if it smells and looks normal. Don't put it back in the fridge. Either cook it immediately or discard it. 

Also Read: 11 Dairy-Free Protein Shakes 

Test 2: The Egg Float Test [What Sinking or Floating Really Means] 

This is the most well-known egg freshness test. It's fast, easy, and works without cracking the egg open. 

What To Do? 

What You’ll See: 

How It Works: 

Eggshells are porous. As an egg ages, moisture and carbon dioxide escape through the shell, and air enters in their place. The older the egg, the larger the air pocket inside, and the more buoyant it becomes. 

Important: the float test has limits. 

A floating egg is a strong sign that it's old. But old doesn't automatically mean spoiled egg. An egg that floats may still be edible. It just needs the crack-open sniff test to confirm.  

Likewise, an egg that sinks is not automatically safe. A contaminated egg can pass the float test and still carry bacteria. Always follow up with the crack-open test if you have any doubts. 

Test 3: The Shake Test [What That Sloshing Sound Means] 

This one takes just two seconds. 

How To Do It: 

What you hear: 

NOTE: A sloshing egg doesn't mean it's rotten. It means it's older and the internal structure has loosened. Always follow up with the crack-open test before deciding. 

Test 4: The Crack-Open Test [What Fresh vs. Bad Eggs Look and Smell Like] 

The most accurate test of all. This one won't lie to you. 

What To Do? 

Crack the egg onto a clean plate or into a bowl. Inspect it in two ways: how it looks and how it smells. 

What to Look For? 

Quick note on color: A greenish ring around a hard-boiled yolk is NOT a sign the egg is bad. It's a harmless chemical reaction from overcooking or high iron content in the water. See the hard-boiled section below for more on this. 

How it Smells? 

A fresh egg has almost no smell at all. 

A bad egg? You'll know instantly. The smell is sulfuric, sharp, and unmistakably rotten, caused by hydrogen sulfide gas produced as bacteria break down the egg. If you smell anything like this, discard the egg immediately and wash the plate and any surface it touched. 

Important Point of Consideration: Not all contaminated eggs smell bad. Bacteria like Salmonella can be present even when the egg looks and smells completely normal. This is why proper cooking (cooking yolks until firm, reaching 160°F/71°C internally) always adds a layer of protection. 2 

Test 5: The Flashlight/Candling Test [Check Without Cracking] 

This one surprises people. You can actually see inside an egg without cracking it open, using your phone torch or flashlight. 

The method is called candling, and it's the same technique commercial egg producers use on conveyor belts to check thousands of eggs before they reach stores. 

How to do it at home: 

What you're looking for: 

What candling tells you and what it doesn't: 

Candling reveals freshness and structural quality. It does not tell you whether an egg carries bacteria. Always combine it with the float test and crack-open test if safety is a concern. 

Test 6: How to Tell If a Hard-Boiled Egg Is Bad 

Hard-boiled eggs deserve their own section because they behave differently from raw eggs when it comes to spoilage. 

Why hard-boiled eggs spoil faster: 

When you boil an egg, the heat removes the egg's natural protective coating (called the bloom). Without this coating, the shell's pores are exposed, and bacteria can enter more easily. A raw egg in the fridge lasts 3-5 weeks. A hard-boiled egg lasts just up to 1 week, whether it's peeled or not. 3 

Signs a hard-boiled egg has gone bad: 

Note: Hard-boiled eggs already have a mild sulfur smell naturally. What you're looking for is a strong, unpleasant pungency that hits you right away. 

What about the green ring on the yolk? 

You've probably seen that greenish-gray ring around a hard-boiled yolk. It looks off-putting but it's completely safe to eat. It's a harmless chemical reaction between the sulfur in the white and the iron in the yolk, caused by overcooking or high iron content in cooking water. It has nothing to do with spoilage. 

Peeled vs. unpeeled: 

Important Note: Refrigerate hard-boiled eggs within 2 hours of cooking. Don't leave them at room temperature longer than that. 

What Happens If You Eat a Bad Egg? 

Eating a spoiled or contaminated egg puts you at risk of food poisoning. The most common culprit is Salmonella Enteritidis, bacteria that can live inside an egg even when it looks and smells perfectly normal. 

Symptoms typically appear within 6 hours to 6 days after eating a contaminated egg.2 They include: 

How long do symptoms last? 

Most people recover on their own within 4 to 7 days. Stay hydrated, diarrhea and vomiting can lead to dehydration quickly. 4 

When to see a doctor 

Who is most at risk 

Pregnant women, adults over 65, young children under 5, and anyone with a weakened immune system are most vulnerable to severe complications from egg-related food poisoning.  

For these groups, the USDA recommendation is especially important: When in doubt, throw it out. 

Can Stale Eggs Still Be Used for Baking? 

Older eggs can actually be better for certain things. An egg that floats or stands upright isn't automatically destined for the bin, as long as it passes the crack-and-sniff test. Here's how to make the most of older-but-safe eggs: 

Best Storage Tips to Keep Eggs Fresh for Longer 

Here are a few small habits that make a big difference. 

When to Discard the Eggs? 

No one likes wasting food. But some signs mean the egg has to go, no second-guessing. Discard eggs immediately if: 

The USDA strongly recommends the principle: When in doubt, throw it out. This is especially important for foods like eggs that may pose a risk if spoiled or improperly handled. Also, this advice stands crucial for pregnant women, older adults, or anyone with a weakened immune system. 

NOTE: Don’t just throw a bad egg out. Be sure to clean any surfaces or utensils that came in contact with the egg to prevent cross-contamination. 

Summing Things Up 

Eggs are a kitchen staple. But they are good only when they’re fresh. And fortunately, it takes less than a minute to find out.  

Start with a visual check on the shell. Do the float test. Shake it. And when in doubt, crack it open and trust your nose. Between these six tests, you'll know exactly what you're working with before it ever hits the pan. 

A few seconds of checking can save your meal, your stomach, and the peace of mind of anyone cooking for family. 

When it comes to doubtful eggs, it’s just not worth the risk. If something feels wrong, trust your gut and let it go. 

Frequently Asked Questions 

Q1. Can I eat eggs past the expiration date? 

Yes, if they've been refrigerated and pass the freshness tests. The printed date is a quality guideline, not a safety cutoff. 

Q2. Does the egg float test really work? 

It reliably shows age, not safety. A floating egg is old, but crack and sniff before deciding. A sinking egg isn't automatically safe either. 

Q3. Are eggs safe after the expiration date?  

Often yes. The USDA says eggs are safe 3-5 weeks from the pack date, usually longer than the printed date suggests. 

Q4. What do spoiled eggs smell like? 

Spoilt eggs smell pungent, sulfuric, and unmistakably rotten. You'll know immediately. 

Q5. Can you eat eggs that float in water? 

Crack it open first. If it smells fine and looks normal, it may still be usable for baking or hard-boiling. Any bad smell, discard it. 

Q6. How long do eggs last in the refrigerator? 

Q7. What happens if you eat bad eggs? 

Risk of Salmonella poisoning; diarrhea, cramps, fever, vomiting. Symptoms appear within 12-72 hours and last 4-7 days. Seek medical help if severe. 

Q8. Are cracked eggs safe to eat? 

Only if cooked immediately and they smell normal. Don't store a cracked egg, cook it or discard it. 

Q9. Can eggs go bad without smelling?  

Yes. Salmonella produces no detectable odor. Always cook eggs thoroughly (yolks firm, internal temp 160°F/71°C). 

Q10. How do I know if farm eggs are fresh without a date?  

Use the same six tests. They work just as well on farm eggs as store-bought. Start with the float test, then shake it, and crack it open if you're still unsure. Farm eggs with an intact bloom (unwashed shell) tend to stay fresh longer, but the tests will tell you exactly where they stand. 

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