How to Tell If Eggs Are Still Good
Do you have a carton of eggs that have passed their use-by date? You can generally safely eat eggs for several weeks past their stamped expiration date, but it's best to run a quick test to see if your eggs are still OK to eat. The test takes only a few seconds and could save you from throwing away perfectly good eggs.
The Egg Test
Fill a bowl with cold water and place your first egg inside. If the egg sinks to the bottom, it's fresh. If the egg sinks to the bottom but stands on its point, it's still good but needs to be used soon. If the egg floats to the top, discard it. Repeat the test with the rest of the eggs in your carton. Don't assume that they're all good or bad because one egg tested that way.
Why This Works
Since egg shells are porous, the liquid inside the egg evaporates over time and is replaced by outside air, resulting in more buoyant eggs. As a result, you end up with fresh eggs that sink to the bottom and old eggs that float to the top. Still, always discard any eggs that have an odd appearance or odor, or that have been stored improperly—even if they passed the sink test. It's not worth the risk of getting sick.
How Long Do Eggs Stay Good?
The Food and Drug Administration and Egg Safety Council both say a reasonable use-by date is four to five weeks after the eggs were packed. The Department of Agriculture requires all graded eggs to have their pack date stamped on the carton. You'll usually find it on one of the ends, near the sell-by or expiration date.
But interpreting the pack date will take a bit of math. It's listed as a Julian date, so it will be a three-digit number. Jan. 1 would be listed as 001, and Dec. 31 would be listed as 365. You'll need to do some counting to figure the pack date on your egg carton, but it's worth the effort. The pack date is a more reliable indication of freshness than the use-by or expiration date, so don't just chuck your eggs because the use-by date has passed.
Keep Eggs Fresh Longer
If your eggs aren't staying fresh as long as you'd like, it could be the way you're storing them. Many refrigerators come equipped with egg compartments in the door, but that's actually the worst place in the fridge for them. Tuck your eggs in the main part of the fridge, where it's colder and the temperature is more stable.
Have chickens? Don't wash your eggs until you're ready to use them. They have a covering, known as bloom, that protects them from bacteria. Leave eggs intact until you're ready to cook them, and your home-grown eggs should outlast grocery store varieties.
You can freeze eggs to prolong their life and use later in cooking. And once you're finished with the eggs, you can use eggshells in your garden. If you run out of eggs—or you find that the eggs you just tested are no longer any good—there are plenty of good egg substitutes you can use in their place.