a basket of free range, farm fresh eggs

Do Eggs Go Bad? Float Test, Shelf Life and Carton Dates Explained

There is a carton of eggs in the fridge and the sell-by date was two weeks ago. Or you found eggs that have been sitting on the counter and are not sure whether they are still safe. Do eggs go bad?

The short answer: Yes, eggs go bad, but the dates on the carton are not the whole story. According to the USDA, raw shell eggs kept refrigerated are safe for 3 to 5 weeks after purchase, even if that takes them past the sell-by date. The float test most people rely on does not tell you what you think it tells you. And hard-boiled eggs are a completely different situation with a much shorter shelf life than raw eggs.

For a full overview of how perishable foods compare on shelf life, visit our Complete Food Storage Guide.

Key Takeaways

  • Raw shell eggs refrigerated: safe for 3 to 5 weeks after purchase, per USDA. Often good past the sell-by date.
  • Hard-boiled eggs: 1 week refrigerated only. Cooking shortens shelf life significantly.
  • The float test: a floating egg is old, not automatically unsafe. Crack and smell to confirm.
  • The sell-by date is not an expiration date. USDA-graded eggs can be safe 4 to 5 weeks beyond the Julian pack date.
  • The smell test after cracking is the most reliable spoilage indicator. A sulfur or rotten odor means discard immediately.
  • The 2-hour rule applies: refrigerated eggs left at room temperature for more than 2 hours should go back in the fridge or be discarded.

How Long Do Eggs Last?

Egg shelf life depends on how they are stored and whether they are raw or cooked. The USDA has specific guidance for each situation.

Egg Type Refrigerator Freezer
Raw shell eggs (in carton) 3 to 5 weeks from purchase Do not freeze in shell
Raw egg whites 2 to 4 days Up to 12 months
Raw egg yolks 2 to 4 days Up to 12 months
Hard-boiled eggs (in shell) 1 week Not recommended
Hard-boiled eggs (peeled) 1 week in water or airtight container Not recommended
Scrambled or fried eggs 3 to 4 days Up to 3 months
Egg dishes (quiche, casseroles) 3 to 4 days Up to 3 months

Shelf life guidelines from the USDA FoodKeeper app and FDA safe food handling guidance. Always check eggs for spoilage before using regardless of date.

Understanding the Dates on Your Egg Carton

Sell-By, Pack Date, and Expiration: What They Actually Mean

Most egg cartons carry two or three different date codes, and most people misread them. Here is what each one means.

The Julian pack date is the most important number on the carton. It is a three-digit code printed on the short side of the carton, representing the day of the year the eggs were washed, graded, and packed. January 1 is 001, December 31 is 365. A carton stamped 032 means the eggs were packed on February 1. According to the USDA and the Egg Safety Center, eggs are safe to eat 4 to 5 weeks beyond this pack date when kept continuously refrigerated.

The sell-by date is a store management date. On cartons carrying the USDA grade logo, the sell-by date cannot exceed 30 days after the pack date. This does not mean the eggs expire on that date. It means the store should replace them by then. Eggs purchased before the sell-by date are typically still safe for another 3 to 5 weeks at home.

The expiration or EXP date is optional and not required by the federal government, though some states require it. It does not represent a hard safety cutoff either. The USDA recommends buying eggs before the sell-by or EXP date and using them within 3 to 5 weeks of purchase.

The Float Test: What It Actually Tells You

The float test is one of the most commonly misunderstood egg freshness checks. Here is the accurate version.

An eggshell is porous. As an egg ages, moisture and carbon dioxide slowly escape through the shell and are replaced by air. This gradually enlarges the air cell inside the egg at the wide end. A fresh egg has a tiny air cell and sinks immediately, lying flat on the bottom of the bowl. As it ages, the growing air cell makes it more buoyant: it begins to tilt upward at the wide end, then stands upright on the bottom, and eventually floats.

The important nuance: a floating egg is old and lower in quality, but the USDA explicitly states it may still be safe to eat. Floating tells you the egg has a large air cell from age. It does not tell you whether bacteria are present. To determine that, crack the egg into a bowl and smell it. If it smells like sulfur or rotten, discard it. If it smells normal, it is safe to cook and eat.

Float Test Result What It Means What to Do
Sinks, lies flat Very fresh, small air cell Use normally
Sinks, tilts upward or stands upright 1 to 3 weeks old, larger air cell; still good. Great for hard-boiling (peels more easily) Use normally
Floats Old, large air cell. Quality has declined. Not automatically unsafe Crack into a bowl, smell it. Use if it smells normal. Discard if any sulfur odor

Signs That Eggs Have Gone Bad

When to Throw Them Out

Sulfur or rotten smell after cracking: The most reliable spoilage indicator. The USDA confirms that a bad egg will give off a foul odor when cracked, even after cooking. Always crack eggs into a separate bowl before adding them to a recipe so you can smell and inspect before they go in. There is no mistaking the sulfur smell of a rotten egg.

Off smell through the uncracked shell: Very old or severely spoiled eggs can smell bad before cracking. If you notice an unpleasant odor from an uncracked egg, discard it immediately.

Pink, green, or iridescent egg whites: Any unusual coloring in the egg white after cracking indicates bacterial contamination. Discard immediately. Note that a green ring around a hard-boiled yolk is not a spoilage sign; it is the result of overcooking or high iron in the cooking water, and it is safe to eat.

Runny, watery white that spreads excessively: As eggs age, the proteins in the white break down and it becomes increasingly thin and watery. A very runny white is a sign of an old egg with diminished quality. It is not necessarily unsafe but will not perform as well in recipes requiring structure, like meringues or soufflés.

Cracked shell: A cracked egg shell allows bacteria to enter. Do not purchase eggs with cracked shells. If an egg cracks in transport, transfer the contents to a clean sealed container and use within two days.

Floating and smelling off after cracking: If an egg floats and also smells wrong when cracked, discard it.

Why Hard-Boiled Eggs Go Bad Faster Than Raw

This surprises most people. Cooking an egg actually shortens its shelf life rather than extending it. A raw egg in its shell has natural antimicrobial properties in the egg white and the protective shell membrane. Hard-boiling removes those properties and the heat makes the shell slightly more porous. Hard-boiled eggs in their shells last one week refrigerated. Peeled hard-boiled eggs last the same one week when stored in water or an airtight container. Do not store hard-boiled eggs in their original egg carton.

How to Store Eggs Properly

Storage Best Practices

Keep eggs in their original carton. The carton protects the eggs from absorbing refrigerator odors through the porous shell and cushions them against cracks. It also retains the pack date so you always know how old they are.

Store on a main shelf toward the back, not in the door. The egg tray in the refrigerator door is the worst place for eggs. The door is the warmest part of the fridge and experiences the most temperature fluctuation. A consistent cold main shelf is better.

Keep at 40°F or below. The FDA requires egg producers to maintain 45°F from 36 hours after laying through retail. At home, keep your refrigerator at 40°F or below for maximum egg freshness and food safety.

Do not wash eggs before storing. Store-bought eggs are already commercially washed. Rewashing removes any residual protective coating. If an egg has a spot of dirt, wipe it dry rather than washing it.

Store large end up. The air cell is at the large end. Storing eggs with the large end up keeps the yolk centered and reduces the chance of bacteria migrating toward the yolk from the air cell.

Do not return eggs to the fridge after they reach room temperature if they were left out more than 2 hours. Once a refrigerated egg warms to room temperature, condensation can form on the shell when it returns to the cold, which can introduce bacteria through the porous surface. If eggs were out for less than 2 hours, returning them to the fridge is fine.

Recipes That Use Eggs

Frequently Asked Questions

My eggs are two weeks past the sell-by date. Are they still good?

Probably, if they have been continuously refrigerated. The sell-by date on USDA-graded eggs cannot exceed 30 days after the pack date, and eggs are safe for 4 to 5 weeks beyond the pack date. This means a carton bought near its sell-by date could have eggs that are safe for another 2 to 3 weeks at home. Do the float test, then crack each egg into a bowl and smell it before using. If it smells and looks normal, it is safe. If there is any sulfur odor, discard it.

Is it safe to eat an egg that floats?

According to the USDA, a floating egg is not automatically unsafe. Floating indicates the egg has a large air cell from age, meaning it is older and lower in quality. It may still be perfectly safe to eat. Crack the egg into a separate bowl and smell it before using it. If it smells normal with no sulfur or rotten odor, it is safe to cook and eat. If there is any off smell, discard it. Do not eat a floating egg raw or soft-cooked; cook it thoroughly to 160°F as an additional safety measure.

I left eggs on the counter overnight. Are they still safe?

Store-bought refrigerated eggs left out overnight have exceeded the FDA 2-hour guideline. Whether they are safe depends on the room temperature and how long they were out. In a cool kitchen at around 65°F they may still be acceptable; in a warm kitchen they are a greater risk. The USDA advises that refrigerated eggs should not be left at room temperature for more than 2 hours. If in doubt, crack each one into a bowl and smell it before using. If you are cooking for anyone who is pregnant, elderly, very young, or immunocompromised, discard them.

Further Reading

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