4 Signs That an Egg Is Bad (According to an Expert)

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Private chef and food educator Ollie George Cigliano explains how to tell if an egg is bad before and after cracking it

Co-authored by Ollie George Cigliano and Elaine Heredia, BA

Last Updated: December 9, 2025 Fact Checked

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Identifying a Bad Egg

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Testing for Freshness

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What happens if you eat a bad egg?

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Egg Storage

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Video

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Warnings

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Have you ever been in the middle of baking or cooking, only to notice your eggs are past the "best-by" or "sell-by" date? Before you throw your eggs away, read our guide to identifying a bad or spoiled egg below. We'll also explain what happens if you eat a bad egg, how to test an egg for freshness, and how to store eggs to make them last longer, with egg-cellent advice from private chef and food educator Ollie George Cigliano.

How to Tell a Bad Egg from a Good Egg

An illustration of eggs undergoing the float test to determine if they're good, okay, or bad.

Private chef and food educator Ollie George Cigliano says to fill a bowl or sink with cool water and put your eggs in it. If they sink to the bottom or bob in the middle of the water, they're safe to eat. If they float to the top, that means they have an air pocket inside them and could be contaminated. Throw them out.

Section 1 of 4:

How to Identify a Bad Egg

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1
Place the egg in a bowl or glass of cold water and see if it floats. Cigliano explains that there's a tiny air pocket inside every egg. Over time, more and more air passes through its porous shell, and the air pocket grows larger, making the egg more buoyant. This air pocket can hold bacteria, so an egg that floats isn't safe to eat.^{[1]
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Expert Source

Ollie George Cigliano
Private Chef & Food Educator

Expert Interview}
- If the egg lies on its side on the bottom of the bowl, it's at peak freshness.
- If the egg stands upright on one end but is still touching the bottom, it's aging past its prime, but is still safe to eat.
- If the egg is floating, it could be contaminated with Salmonella, so you should throw it out to be safe.
Meet the wikiHow Expert

Ollie George Cigliano is a private chef and food educator with over 20 years of experience. She specializes in utilizing fresh, fun ingredients and mixing traditional and innovative cooking techniques.
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Break the egg open and notice if it smells. According to Cigliano, a bad egg will have a pungent, foul odor when you break it open.^{[2]
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Expert Source

Ollie George Cigliano
Private Chef & Food Educator

Expert Interview} The sulfurous smell will be obvious as soon as the egg is cracked (and possibly before), and you should throw the egg away.^{[3]
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- A bad egg will have this foul smell, regardless of whether it's raw or cooked.^{[4]
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  Food Safety and Inspection Service of the USDA
  Food safety information provided by the U.S. Department of Agriculture.
  
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Break the egg into a small dish and inspect the color. The color of the yolk will change based on the diet of the hen that laid it, so the shade of yellow or orange has nothing to do with freshness. Instead, inspect the egg white, or albumen.^{[5]
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Food Safety and Inspection Service of the USDA
Food safety information provided by the U.S. Department of Agriculture.

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- If it's pink, green, or iridescent, the egg has been contaminated by Pseudomonas bacteria and isn't safe to eat.
- If you see black or green spots inside the egg, it's been contaminated by fungus and should be thrown away.
- If the yolk of a hard-cooked egg has a green ring around it, this means the egg has been overcooked or was cooked in water with a high iron content. This egg is still safe to eat.
- If there is a blood or meat spot on the egg, it's still safe to eat and does not mean the egg is contaminated or has gone bad. A blood spot occurs when a blood vessel ruptures when the egg is forming and has nothing to do with freshness.
Once an egg has cooled in your refrigerator, it's important to keep it at the same temperature. A cool egg in a warmer environment, such as room temperature, begins to sweat, which can encourage bacteria to grow on the outside of the egg. Because the egg shell is porous, it's sometimes possible for the bacteria on the shell to pass through and contaminate the egg.^{[6]
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Section 2 of 4:

How to Test an Egg for Freshness

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1
Hold the egg up to your ear and shake it, listening for a sloshing sound. As the egg ages and moisture and carbon dioxide escape through the shell, the yolk and white begin to dry out and shrink. This causes the air pocket in the egg to get bigger. A larger air pocket gives the egg more room to move around inside the shell and create a sloshing sound.^{[7]
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- A fresh egg should not make much, if any, sound when you shake it.
- A sloshing egg only indicates that the egg is old and doesn't mean the egg is unsafe for consumption.
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Crack the egg open on a plate and check the yolk and white. The integrity of the egg will lessen as it ages, so it won't hold together as well as a fresh egg. Notice if the egg seems to spread over a wide distance on the plate, or if it stays relatively compact. An egg that spreads or seems a little watery has a thinner white and is past its peak freshness. Look at the color of the egg white, as well. A cloudy white indicates a very fresh egg. A clear white means the egg is older (but may still be edible).^{[8]
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Food Safety and Inspection Service of the USDA
Food safety information provided by the U.S. Department of Agriculture.

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- If the yolk is flat and breaks easily, the egg is old.
- If the yolk moves around easily, this means the chalazae (the thicker strands of egg white that hold the yolk in place) have weakened, and the egg is aging.
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Use the 3-digit code that tells you when the eggs were packaged. Sell-by or best-by dates are not required by federal law (some states require them, other states forbid them), but all eggs must be labeled with the date they were packaged. This date usually appears as a 3-digit code using the Julian date calendar. This means eggs packaged on January 1st would be labeled 001, eggs packaged on October 15th would be labeled 288, December 31st 365.^{[9]
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US Department of Agriculture
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- Look for the Julian date on the end of the carton. You'll see the plant code (a letter P followed by numbers) indicated where the eggs were packaged, and beside it, you should find the Julian code.
- The European Union also requires that eggs be marked with a pack date. Even if eggs are sold loose and not in a marked carton, the consumer should have access to that information.^{[10]
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Check the "best-by" date on the package. It may also be labeled as "use by," "use before," or "best before." "Best-by" refers to the period of time eggs are at peak freshness, with the best texture, flavor, and binding and thickening properties.^{[11]
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Research source} It doesn't mean the eggs are bad or rotten after this date, however. Try to use these eggs within 2 weeks after the best-by date.
- In the US, the best-by date must be within 45 days of the date the eggs were packaged.^{[12]
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  Food Safety and Inspection Service of the USDA
  Food safety information provided by the U.S. Department of Agriculture.
  
  Go to source}
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Check the "sell-by" date on the package. The sell-by date may also appear as "not to be sold after" or "EXP." "Sell-by" refers to the last date the eggs should be available for the public to purchase. Eggs should be pulled from the shelf after this date.^{[13]
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Research source} Your eggs aren't always bad or rotten after this date, though. Eggs that are kept refrigerated and aren't broken should be good for at least 1 month beyond the sell-by date.
- The "sell-by" date is, at most, 30 days from the day the eggs were packaged.^{[14]
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Section 3 of 4:

What happens if you eat a bad egg?

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Other potential symptoms of Salmonella poisoning are fever, chills, and a headache. The good news is you should feel better within a few days as your body purges the bacteria from your system. If it lasts longer than 4-5 days, or you experience a high fever or blood in your stools, see a doctor right away.^{[15]
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Mayo Clinic
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Section 4 of 4:

How to Store Eggs to Make Them Last Longer

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Keep store-bought eggs in a carton in your fridge for 3-5 weeks. Avoid storing them on the door, since opening and closing the door causes the temperature to fluctuate too much and makes your eggs sweat. Keeping them in the carton they came in from the store prevents them from losing moisture. It also protects them from absorbing odors and flavors from nearby foods.^{[16]
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- How long are hard-boiled eggs good for? Hard-boiled eggs can last for up to 1 week if you leave them in their shell. After you peel it, eat it the same day.
If you get your eggs unwashed and at room temperature, they don't need to be refrigerated until you wash them. Many countries, including most European countries, keep their eggs at room temperature.^{[17]
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Research source} This is safe because eggs are laid with a protective "bloom," an invisible protein coating on the shell that naturally keeps bacteria out. Also, in most European countries, the hens have been inoculated against Salmonella prior to laying their eggs.
Once you wash the bloom off your farm-fresh eggs, Cigliano says you must refrigerate them immediately.^{[18]
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Expert Source

Ollie George Cigliano
Private Chef & Food Educator

Expert Interview} Put them in a clean egg carton, pointy end down, and expect them to stay good for up to 3 months. Write the date you put them in the fridge on the carton or set a reminder on your phone so you don't forget.^{[19]
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Use your country's packaging guidelines to determine how long to keep your own eggs. If you have egg-laying hens and you're wondering when they will go bad, refer to your country's guidelines for freshness. It's a safe bet your eggs will be good for at least 2 months, if not longer.
- If you're not sure how long you've had your fresh eggs or if you think they're older than 2 months, learn the signs of bad and old eggs to help you decide whether you should use them in your cooking.

Join the Discussion...

How do you tell if eggs are bad?

WikiSealChaser638

I need eggs for a recipe, the ones in my fridge have been there have been there for I don't even know how long. It looks like I'm only a little bit past the "best by" date, but I don't want to risk using bad eggs and getting sick from it. Is there any way to check an egg without cracking it open? About how long are eggs really good for?

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Warnings

When cooking eggs for high-risk individuals (the very young or elderly), you may want to only use eggs at peak freshness. While eggs are generally safe for weeks after their expiration date, take extra precautions when feeding those with lowered immune systems and stick to just the freshest eggs.

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