How to Tell If Your Eggs Are Bad

You know that date stamped onto your egg carton? It's not actually an expiration date; eggs are usually good well past that date. In fact, if you've kept the eggs in their carton and in a chilly refrigerator, they can be good for weeks beyond the stamped date. But if you don't go by that date, how can you be sure your eggs haven't gone bad?

Here's how to tell if your eggs are still fresh even after the "best by" date has sailed on past.

The Fresh Egg Water Test

Fill a bowl with water, and carefully place an egg on top. If the egg sinks like a stone, laying down on its side, it's still very fresh! If it sinks but doesn't lay flat—and instead it kind of stands up, wobbling—your egg is OK and probably just right for hard-boiling. Egg salad, anyone? If the egg floats on the top, that's an indication that your egg is possibly past its prime. Floating doesn't necessarily mean it's gone bad, just that it's no spring chicken, as it were. But better safe than sorry. When in doubt, throw it out.

How Old Are Your Eggs?

If you look at the date stamped on your carton of eggs, you'll notice a recognizable date ("SELL BY MAY 11," for example). You'll also notice two sets of additional numbers: They may seem a little random, but they're actually indicating 1.) the packing date for the eggs and 2.) the plant in which they were packaged—an important indicator in the event of a recall.

As for the packing date, it's very easy to understand once you know what's what. This set of numbers runs 1 through 365, which is (not coincidentally) the number of days in the year. So, if the number on the carton is 032, for example, you know that because there are 31 days in January, the eggs were packed on February 1, which is the 32nd day of the year. Eggs are generally packed very soon after they're laid.

If your eggs are beyond the "best by" date but they've passed the water test—meaning, they were packed a reasonable amount of time ago and they wobbled or sank onto their sides in water rather than floating on top—crack one open.

Obviously, if you crack open an egg and it smells bad, it's fit for the garbage. But there are a few more subtle things to look for. A fresh egg will have a bright orange yolk and the whites will still have some spring to them. If the yolk is dull and yellowish and the whites run out lifelessly onto the plate, the egg is old. But again, an older egg isn't necessarily a bad egg. So give it a sniff; your nose will know. An egg should have a neutral smell. If there's no funky odor, it's probably OK. If you pick up sour or mildewy notes on the nose, toss it.

If your eggs are approaching the "best by" date, and you'd feel better cooking them, make pickled eggs! We have a bunch of recipes for pickled eggs. It's a terrific, tasty way to preserve your eggs.

But don't think that simply boiling your eggs will preserve them. Boiling them, in fact, may do the opposite and speed up their demise. Once you boil an egg it stays fresh for only about a week. This means you could take half the eggs from a carton of fresh eggs, boil them, and those eggs could go bad well before the raw eggs that you left alone. Though it sounds strange, it actually makes sense: The boiled eggs go bad faster because boiling removes a naturally occurring waxy covering that protects the raw eggs from bacteria. Without it, bacteria can sneak through the porous shells.

How Can You Tell If Hard-Boiled Eggs Are Bad?

The best way to test if your eggs are still good after you've boiled them is, again, the smell test. Basically, you'll notice the smell is off if an egg is starting to go bad. This is true for raw eggs and it's true for boiled eggs—the funk doesn't lie.

What Happens When You Eat a Bad Egg?

If a bad egg somehow sneaks past your sniffer and you eat it, you could be in for some unpleasant stomach upset. But beyond eating an egg that's gone bad, there is the issue of eggs that are tainted with salmonella bacteria. The good news is, contamination is very rare—estimates range from one in every 10,000-30,000 eggs are infected with salmonella. Unlike good eggs that have simply gone bad, an egg infected with salmonella won't smell bad. Symptoms of salmonella poisoning include vomiting, fever, diarrhea, and stomach cramps. They typically appear within 12-72 hours of eating the infected food and may last several days. The Centers for Disease Control and Prevention (CDC) reports that although most people will recover without medical treatment, "in some cases, diarrhea may be so severe that the patient needs to be hospitalized...The elderly, infants, and those with impaired immune systems are more likely to have a severe illness."

You can help protect yourself from salmonella by following these tips.

Quick Tips for Staying on the Safe Side

• Buy eggs that are sold in refrigerated cases.
• Store your eggs in their carton in the refrigerator at 40 degrees F or below.
• Don't wash your eggs until you're ready to prepare them.
• Toss out cracked eggs. Bacteria can sneak through cracks.
• Leave hard-boiled eggs in the fridge in their shells. Don't peel the eggs until you're ready to eat them.

Check out our collection of Breakfast Egg Recipes.