The Egg Float Test

      The Egg Float Test

June 13, 2021

(A really old store-bought egg vs a really fresh backyard egg in the Egg Float Test!)

In a perfect world, your chickens would lay eggs in their nesting boxes each morning, you would collect them, bring them into the house and prepare them to eat. Mmmm, fresh eggs every day like clockwork. Of course, real life doesn't work quite like that. It seems it's either feast or famine around here - too many eggs or not enough. When you have extra eggs and they start to pile up, unless you mark or otherwise keep track of how old the eggs are, it's easy to lose track. If you let your chickens free range, you might stumble across a nest of eggs that a sneaky broody hen has hidden and have no idea when they were laid. These are affectionately called 'yard eggs' and normally perfectly fine to eat as long as they aren't cracked. (Of course if you have a rooster, they could be fertile and if the hen has been consistently sitting on them, they could be developing...but that's a topic for another post. But don't worry, as long as the hen is still amassing her clutch and not sitting full-time, they won't have started to develop yet.) Anyway, my point is that there are lots of reasons why you might start to lose track of just how old some of the eggs on your counter are. But there's an easy way to tell just how old an egg is. And I'll show you!

Eggs will keep a lot longer than you probably realize.  Generally, an egg will last un-refrigerated out on the counter at room temperature, unwashed, for at least two weeks. Unwashed and stored in the refrigerator, an egg will last a lot longer - more than three months. Even washed eggs will last for about two months in your refrigerator. But when in doubt, just do the Egg Float Test for freshness. It's simple. Just fill a clear glass with warm water (cold water can cause any bacteria on the shell to be drawn into the egg) and gently drop the egg in. 

• Freshly laid eggs will lie flat on the bottom of the glass.
• After 1-2 weeks, one end of the egg will begin rise off the bottom of the glass.
• After 2 months or so, the egg will likely be standing straight up with just the pointy end touching the bottom of the glass.
• Eggs older than 3 months will likely float and should be tossed out.

As the egg ages and air seeps through the pores in the eggshell, the air sac inside the egg enlarges as the inside of the egg start to dry out. That causes one end of the egg to rise. By the time it's two to three weeks old, an egg will begin to lift up off the bottom of the glass.  The egg is also losing valuable nutrients as it ages. By the time the egg is a month or two old, it will be visibly angled in the glass, but still perfectly good to eat, and by three months the egg will mostly likely be standing straight up. However, as long as one end of the egg is still touching the bottom of the glass, the egg is fine; and while it won't taste as fresh, it will peel far better if you hard-boil it. Floating eggs are very old and have most likely gone bad (or at the very least are very old) and should be thrown out. Some people dispute that and say that a floating egg still might be okay to eat, but at the very least, by the time an egg starts to float it is extremely old and so much air (and possibly bad bacteria) has passed through the shell that the egg now floats. Some say you can still eat a floating egg, but why chance it, especially when you have fresh eggs at your disposal? I would toss any egg that floats. The one downside to the float test is that once you've submerged the egg, the water will wash off the "bloom" which is the natural coating that keeps an egg fresh. So if it wasn't previously, that egg will need to be refrigerated and won't stay as fresh is it might have with the bloom still intact.

If you want to keep the bloom intact, shake the egg. If you hear sloshing inside, it has likely gone bad and shouldn't be eaten. At the very least, it's old. And of course if you crack an egg and it smells bad...really bad....or is discolored and cloudy, then it's  obviously no good to eat and needs to be tossed. So next time you discover a broody hen's secret cache, or aren't able to keep up with the egg supply in your refrigerator, don't throw the eggs away, just pop them into a glass of water before using them. Most likely they are perfectly good to use. Remember though, that dunking the eggs will remove the natural "bloom" on the egg that keeps them fresh, so once you've done the Float Test on an egg you should use it right away or refrigerate it. Hopefully this helps you determine how fresh your eggs are!