How to tell if the eggs in your fridge are still good to eat

• Eggs are often perfectly safe to eat past their sell-by date.
• If an egg floats in a bowl of water or has a sulfurous smell once cracked, it's no longer safe to eat.
• It's best to store eggs in their carton in the fridge and avoid washing or handling them.
• Visit Insider's Home & Kitchen Reference library for more stories.

Since eggs come so conveniently packaged in their own container – their shell – it can be a bit tricky to tell if they're still good and safe to eat before you crack it open.

"Salmonella is the biggest concern when it comes to consuming bad eggs, not to mention your scramble isn't going to taste so good, either," says Kelly Unger, Director of Compliance at Happy Egg Co. Fortunately, there are a few easy tricks to tell if your eggs are fresh.

First, store your eggs properly. "We always recommend following the USDA's standards for safe egg storage – keeping them refrigerated at 40 degrees [Fahrenheit] or below," says Unger.

And don't go by the sell-by date. Eggs will typically keep in the fridge for three to five weeks after purchase, often surpassing the date stamped on the side. If you're not sure how long your eggs have been hanging out in the fridge, try some of these fresh test methods.

Use the float test

"We always tell our consumers to try the egg float test," says Unger. Fill a bowl with enough water to cover the egg by at least an inch and carefully place the egg in the bowl.

If the egg remains on its side at the bottom of the bowl, it's fresh and safe to use in your favorite recipe. If the egg stands on its end or at an angle, with part of the egg floating slightly, the egg is still safe to eat, it's just not as fresh. Use this egg for baking and avoid using it for raw applications or poaching.

If the egg floats and loses contact with the bottom of the bowl, it's too far gone and should be discarded. "The floating has to do with the size of the air cell acting like a balloon. The bigger the air cell, the more the egg can float," says Unger.

She explains that the air cell grows because the moisture in the egg is seeping out through tiny pores in the shell, replaced by air. This does not mean the egg is bad but rather means that the egg has aged and should be used in applications where it will be fully cooked.

Use your nose

Everyone's familiar with the unpleasant odor of rotten eggs. When in doubt, follow your nose - one surefire sign of a bad egg is the smell. "Typically, you'll be able to tell that an egg has gone bad upon cracking it open. If an egg is bad, it will give off a sulfur-like odor," says Unger.

Use this method in addition to other fresh checks, since an old egg isn't guaranteed to smell bad enough to catch your attention.

Use your eyes

Give your eggs a thorough inspection. Eggs with cracks in the shell or even hairline fractures should be thrown out. "If you crack open an egg and you see hints of pink or green, that's a typical sign that it's no longer fresh," says Unger.

While any visual anomalies are an indication that something is off, don't assume an egg is fresh if it looks intact with natural coloring. Perform a float test and give them a whiff to double-check.

Candle your eggs

Candling is a method used to determine an egg's grade and freshness, as well as to check if an egg is fertilized. It is so named because it used to be performed with a candle, but candling is now done by using a bright, directional light in a dark room. The egg is held right up to the light to reveal the contents within.

"When candling, you want to look for the air cell, usually located at the larger end of the egg. The smaller the air cell, the fresher the egg," says Unger. While you can candle your eggs at home, it's best left to those with know-how who are familiar with the relative size of air cells in chicken eggs.

Shake your eggs

One popular method for checking an egg's freshness is by shaking it. If the egg doesn't make a sound, it's fresh; if it makes a sloshing or rattling sound, it's old.

Unger doesn't recommend shaking your eggs, though. "Shaking the egg could break the chalaza, the membrane that holds the [inside of the] egg in place," she says. If the membrane breaks, you will hear or feel the whites and yolk moving around regardless of whether the egg is good or bad.

How to keep your eggs fresh for as long as possible

• Store them in the fridge. Eggs will last longer and stay fresher if kept in the refrigerator, so keep them well-chilled.
• Store them in the carton. While some refrigerators come with an egg compartment in the door, don't use it. "Eggs have pores that are protected when they're in the carton versus being exposed in a container or a bowl. This also keeps them at a consistent temperature," says Unger.
• Don't wash your eggs. You may think that giving your eggs a wash will reduce any bacteria, but the opposite is actually true. "Washing eggs removes the protective cuticle layer around the shell, another layer designed to keep bad bacteria out," says Unger.
• Don't handle them too much. Keeping the eggs in the fridge and not removing them or touching them too much will "help maintain their quality," explains Unger. Grab what you need and leave the rest in the carton, safely stashed in the fridge.

Insider's takeaway

To ensure you always have fresh eggs handy, store them in the carton in the fridge and make note of when you bought them. If you're not sure how old your eggs are, use the float test for the most accurate measure of their freshness. If they sink they're good; if they float, they're old and should be discarded.

And remember to trust your senses - if your egg looks or smells off, err on the side of caution and toss it.

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