The humble egg: you might eat them every day, but how much do you know about them? To answer your questions – and probably some you never thought to ask – we got answers from Aimee Mundy of Ellison Family Farm Eggs in Miami (along with some information from trustworthy sources on the Web). Aimee’s Facebook page is a treasure trove of information about buying, storing, and using eggs. 

How Long Are Eggs Good?

Mundy says the most popular question she’s asked is: How long do eggs really last?

The short answer: Eggs can last just fine for two or three months – or even longer. 

Eggs aren’t “bad” until they smell bad, so you don’t need to worry about safety as long as an egg passes the sniff test.

When they’re laid, eggs have a natural protective layer, called the “bloom” or “cuticle,” on their surface that seals off the inside from air and pathogens. When you buy eggs from a local producer, that protective layer is still on the egg. You want it to stay there to help keep the eggs fresh during storage – so it’s usually best to avoid washing eggs until just before you use them.

However, commercially produced store-bought eggs have been washed as part of the production process. So they don’t have that natural protective bloom keeping air and bacteria out. Some stores coat the eggshells in mineral oil to seal them, and that’s why they might appear shiny. This can help store-bought eggs, too, last as long as a few months. 

They have to, because, as Mundy explains, “Farmers can take up to 30 days to get the egg from the chicken to the carton, and eggs can be sold for another 30 days after the date on the carton.” 

So store-bought eggs might be two months old before you even purchase them.

Mundy says eggs that have been stored for a while – as long as they smell okay – “will be fine to eat, just not as fresh. Yolks may be not quite as firm, and the white will be more runny.”

How to know how old your grocery store eggs are:

Somewhere printed on the carton you should see a three-digit number. This number tells you the day of the year when the carton was packed, 001 being January 1 and 365 being December 31. For example, the number 041 would be the 41st day of the year, February 10. Keep in mind that this is the date the carton was packed, and the eggs could be as much as 30 days older.

How to test your eggs for freshness:

Use the “float test” to find out how fresh your eggs are. Fill a bowl with cool water, at least as deep as the egg is tall. Place an uncooked egg carefully in the water and watch what it does. If it lies on the bottom of the bowl, it’s very fresh. If it starts to rise up on one end, it’s older. An egg that floats on the surface is not fresh at all – but it’s still perfectly edible, as long as it smells all right.

How to choose eggs for cooking:

Mundy says for scrambled eggs, the fresher the better. For baking, the best eggs are a week or two old. This time lets the whites “relax” so they will incorporate air better when you beat them. If you have a whole carton of eggs that’s around two weeks old, use them to make meringue.

How to peel eggs: The older they are, the easier they are to peel. Mundy says, “If you’re boiling them on the stove, I wouldn’t even bother unless the eggs are two weeks or older.”

Storing Eggs for Freshness

People often ask whether eggs have to be stored in the refrigerator – and we can answer that question, too. But what might be more important is which way to store eggs: which end goes up?

This is important because much of what happens when eggs lose freshness is that air penetrates into the shell, and at the same time, moisture leaves through the shell. 

Keeping the egg’s natural protective bloom on it – by not washing them – can reduce the air getting in and the moisture leaving, thereby keeping the eggs fresh longer.

But you can also improve eggs’ longevity by storing them with the pointy end down. Have you ever noticed that there’s an air pocket inside every egg, at the rounder end? By keeping that air pocket on top, it helps keep outside air from getting in. Storing them this way also helps protect the yolk, keeping it centered and intact, according to Mundy.

Sometimes you get eggs that are almost perfectly spherical, but if you look closely, you can usually identify one end that’s a little pointier and the other end that’s a little rounder.

If you’ve traveled outside the U.S., you might have noticed that in much of the world, no one refrigerates eggs. In Europe, grocery stores sell eggs at room temperature, with the nonperishables. So why is refrigerating them so common in the United States?

According to Healthline.com, the main reason for refrigerating eggs is to prevent the growth of salmonella. Salmonella can’t reproduce at temperatures below 40°F. 

In Europe, egg producers are required to have their chicken mass-vaccinated to prevent them from producing contaminated eggs in the first place. In the U.S., these vaccinations aren’t required. 

And because American commercial egg producers wash their eggs almost as soon as they’re laid, they eliminate the protective bloom that would have sealed out contaminants. So they have to depend on sanitizing and refrigeration to prevent salmonella. And that’s why eggs are refrigerated in American grocery stores.

Once eggs have been refrigerated, they should be kept that way until right before they’re used. This is because when cold eggs are left out in a warm environment, they will collect condensation – that’s why your eggs get damp after you take them out of the fridge. This layer of condensation is a perfect environment for salmonella to grow. So if you purchase refrigerated eggs, keep them refrigerated. It’s all about safety.

If you do refrigerate your eggs, don’t store them in the door – the constant changes in temperature as the door is opened and closed will reduce the eggs’ quality. Instead, keep them well inside the fridge, where the temperature will stay as constant as possible.

What Do the Colors Mean?

Chicken eggs come in a gorgeous array of colors – white, green, blue, olive, light brown, dark brown, and even pink. 

The colors make eggs beautiful to look at, but they don’t tell you anything about the nutritional value of the egg inside. The color of the eggshell is determined by the breed of the chicken – it has nothing to do with their diet. There’s an old misconception that brown eggs are more nutritious than white eggs, and that isn’t true. 

What’s inside the egg is what matters, and here, the color can give you a clue. Yolk color depends on what the hen was eating when it produced the egg. For example, if the hen was eating a lot of beets, it will produce a dark yellow or even orange yolk. 

But the color doesn’t tell you anything about the protein or fat content of the yolk. Mundy points out that a darker yolk might mean it has more vitamins, but that’s only because the color suggests the hen was eating lots of vegetables.

All eggs are white when they start out. It’s only in the last few hours before it’s laid that the eggshell gets its final coating, including pigment. Mundy says it takes about 20 hours for an eggshell to fully develop.

What about eggs with brown speckles, white patches, striation (bands of different colors), bumps, or rough patches? These are all fine to eat – they only affect the shell, not the egg inside. Brown speckles are just oddities that happen during the coloration of the shell. White patches are harmless deposits of excess calcium. 

Wrinkles in an eggshell can happen if the hen was startled while the egg was being formed, such as by a dog barking. Often, farmers keep these “imperfect” eggs to feed their own families, so customers might never see them.

The only imperfection you’ll see that you really need to be concerned about is cracking. If you find a cracked egg, throw it out. There’s too high a risk of salmonella contamination.

Did you know you can tell the color of the eggs a chicken will lay by looking at its legs? Chickens with yellow legs will tend to lay white or light brown eggs. Chickens whose legs look a little greenish or bluish will generally lay green or blue eggs. It isn’t a foolproof clue, but it can give you a hint.

Have you learned more than you ever thought there was to know about chicken eggs?

If you still have questions, head on over to the Ellison Family Farm Facebook page, where Aimee Mundy posts all about them.