How Do I Tell the Difference Between Fertile Chicken Eggs & Not Fertilized?

Unfertilized eggs are a time bomb in your incubator. When they go bad, infertile eggs can explode and cause a horrible stink, not to mention a gooey mess you have to clean out. Fortunately, there is a way to weed out the eggs that will never hatch, without harming the healthy embryos. Chicken eggs take approximately 21 days to hatch, but you can tell fertilized eggs from unfertilized eggs at six days.

Things You'll Need

  • Flashlight
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Instructions

    • 1
      Unfertilized eggs can make a mess in your incubator.

      Wait until the egg has been incubated for at least three days. If you try to check the fertility before the three-day mark, you won't be able to tell for sure if it is fertile.

    • 2

      Turn off the lights in the room and close the curtains. You need the room dark so all of the available light shines through the egg.

    • 3

      Wrap your hand around the end of a small flashlight, so the light shines through your fist between your thumb and forefinger.

    • 4

      Hold the egg in the other hand, pointed side down.

    • 5

      Press the hand holding the flashlight against the opposite side of the egg. The light from the flashlight should be pointed towards you, with the egg in between. Make sure no light leaks around your fingers, it should be shining through the egg.

    • 6

      Examine the egg for the presence of veins. The veins should look like a spider's web, stretching out from a single point with a dark spot. If you see veins, the egg is fertile. If you're not sure, incubate the egg for a few more days and check again.