Testing Eggs for Freshness

Egg test
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Did you know you can test an egg and get an approximatation of its age? All you need are the eggs and a bowl of cold water. Make sure there's enough water in the bowl to completely cover the egg with about 1/2" left over. Gently drop the egg into the bowl of water. If it:

  • sinks to the bottom and stays there, it is about three to six days old.
  • Sinks, but floats at an angle, it's more than a week old.
  • Sinks, but then stands on end, it's about two weeks old.
  • Floats, it's too old and should be discarded.

For a test just to see if the eggs are all right to use, dissolve 2 tablespoons salt in 2 cups cold water, then put the egg in the water. If it sinks, it's good; if it floats, it's too old.

Eggs act this way in water because of the air sac present in all eggs. As the egg ages, the air sac gets larger because the egg shell is a semi-permeable membrane. The air sac, when large enough, makes the egg float. Eggs are generally good for about three weeks after you buy them.

And how do you see if an egg is hard cooked? Spin it on a flat surface. If the egg wobbles, it's fresh because the insides are moving around. If the egg spins smoothly, it's cooked.

Remember, even with these tips, you should always cook your eggs well done, because Salmonella and other pathogenic bacteria are present in most eggs.

The bacteria can even be inside the shell, so even if you wash the egg or soft-cook it, you could get sick if it's undercooked. Always cook fried eggs over well done, cook scrambled eggs until they are 165°F, and cook hard-cooked eggs until they are completely firm. And always refrigerate eggs, whether cooked or uncooked.

While it's true that most eggs are not contaminated, if one is, you can get very sick. There have been large-scale outbreaks of Salmonella from shell eggs in the past; in 2010, 60,000 Americans were sickened with Salmonella from eggs.

To be safe, especially if someone in your home has a compromised immune system, is pregnant, is young or elderly, think about buying pasteurized eggs. These are eggs that have been quickly heated to a temperature high enough to kill bacteria but low enough so the egg remains uncooked. Follow expirations dates to the letter with this product.

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