Keep your eggs fresh and become an eggspert in telling if they’re still good or not.
Affordable and nutritious, eggs are a true staple in the American kitchen. And for good reason: Not only are they delicious, but the family cook can use them to whip up a dish for any occasion, from fluffy omelets and puffy frittatas to hearty cornbread and thick pancakes.
Like any other perishable food, eggs don’t last forever. Since eating a bad egg can give you or a family member with a weakened immune system a foodborne illness, we wrote up everything you need to know about the proper handling and safe preparation of eggs.
How Long Do Eggs Last?
Let’s start with the basics:
Eggs have a shelf life of 4 to 5 weeks from the date of packaging. The packaging date is a one, two, or three-digit code printed on the side of the egg carton, which represents a date in the Julian calendar.
The Julian date, named after Julius Caesar who introduced it in 45 BC as a reform of the Roman calendar, represent the consecutive days of the year for any given day. The Julian calendar starts with 1 for January 1st and ends with 365 for December 31st (in a leap year, the last day on the Julian calendar is the 366th).
As a general rule, the U.S. Department of Agriculture states on its website that you can store eggs for 3 to 5 weeks from the day you bring them home from the grocery store and put them in the fridge.
A carton of eggs at the grocery store can be stamped with an expiration date, best-by date, or sell-by date; a packaging date; and a plant code. Whereas the packaging date is required by most states, some states forbid the sell-by date.
Here’s what the pack date typically looks like:
To understand your local egg laws, and how they determine exactly what’s printed on the carton, the Institute of Agriculture and National Resources at the University of Nebraska-Lincoln recommends that you contact your state’s Department of Agriculture.
How Long Do Cooked Eggs Last?
Exactly how long cooked eggs last depends on how you cooked them.
Generally speaking, hard-boiled eggs can be stored in the fridge for up to one week. This rule applies only to eggs whose shells have remained intact during boiling. Eggs whose shells cracked during boiling are still safe to eat but have a shorter shelf life.
Omelets, frittatas, scrambled eggs, sunny-side-up eggs, and other cooked egg dishes must be kept in an airtight container in the fridge, where they will keep for 3 to 4 days after cooking.
Store leftover cooked eggs in the back of the fridge. The temperature fluctuations near the door are too great and shorten their shelf life.
How to Store Eggs
How you store your raw eggs depends on where you buy them. Eggs from the supermarket are washed and need to be refrigerated; farm fresh eggs are unwashed eggs and can be stored at room temperature.
Storing Supermarket (Washed) Eggs
In the United States, the Food & Drug Administration requires egg producers with 3,000 or more hens to wash their eggs.
Washed eggs should not be kept at room temperature or they will spoil. Take them home right after you buy them and store them in the lowest compartment of your fridge, where it is coldest, to keep them fresh and maintain their best quality longer.
The washing is usually done with soap, chlorine, or enzymes, The New York Times reports, and aims to prevent 79,000 cases of foodborne illness and 30 deaths per year from contamination with Salmonella.
Washing makes the eggs sparkling clean and kills the Salmonella Enteritidis bacteria on their shells, making them more appealing to us consumers and safer to handle during transportation, storage, and cooking.
However, the washing also destroys the egg’s natural protective coating, called the “cuticle,” which regulates the evaporation of water from the egg shell and protects it from the intrusion of other bacteria.
Storing Farm-Fresh (Unwashed) Eggs
If you have your own chickens or buy fresh eggs from a local farmer who has fewer than 3,000 backyard chickens—and therefore does not have to adhere to FDA requirements—the eggs you eat are unwashed.
Fresh farm eggs with the cuticle intact can be stored at room temperature, but the best way to store them nevertheless is in the fridge, which provides the proper temperature for storing perishable foods.
Unwashed fresh eggs can be kept at room temperature, whether on the kitchen counter or stashed away in the pantry, because their cuticles are still intact and they don’t have a porous shell that lets harmful bacteria in as freely as their washed counterparts.
However, refrigeration keeps the freshness of an egg for longer. Because storage temperatures of 40°F or less slows down the growth of bacteria, refrigerated eggs are generally safer for consumption, especially in the sweltering summer when room temperatures are higher than in other seasons.
A Great Way to Tell If Eggs Are Still Good
If you threw away the original carton and put the eggs in the egg holder in your fridge, you can’t tell if they are still good or not by the expiry date or packing date. After all, you don’t have them anymore.
The Egg Float Test
The good news is that there’s a simple and straightforward test that you can do with a glass of water to determine if raw eggs are still good to cook and eat or not.
Fill a tall glass with cold water, dip the egg in it, and observe:
- If the egg sinks, it’s as fresh as can be.
- If it stays on end or floats at an angle, it’s a couple of weeks old but still good.
- If it floats to the top of the glass, the egg is too old. You have no way of knowing if it’s safe to eat or not, so you should throw it away.
To do this test for lots of eggs at once, dip them in a large bowl of water. If the eggs keep to the bottom of the bowl or flat near it, they’re good. If they float all the way to the top, they’re bad and should be discarded.
This test works so well because as an egg ages, the moisture that it contains slowly but surely evaporates through the shell and gets replaced by pockets of air. Air is lighter than water, so a big air pocket will cause the dipped egg to tilt upward at an angle—and enough big pockets of air will cause it to float all the way up to the top.
The Egg Sniff Test
Give the raw, uncracked eggs a good sniff through the shell. Then trust your senses; they’re there to protect you against old foods that can make you sick. If you notice an off, sulphuric odor, the eggs are most probably rotten and should be discarded immediately.
(You can, of course, crack one egg in a bowl and give it a sniff as well.)