How to find if and egg is not boiled before cracking it. If I have boiled several eggs and after that someone have mixed them with other not boiled eggs, how can I separate them. Of course I don't want to break the eggs.

  • 1
    For the future, you can mark your hard-boiled eggs with a sharpie before you keep them; that way you'll always know.
    – Justin
    Commented Feb 19, 2015 at 16:47
  • 3
    @Quincunx Are sharpies food-safe? Is there a food-safe permanent marking pen? Also you've got to prevent the person mixing the eggs from also marking the non-boiled ones.
    – Random832
    Commented Feb 19, 2015 at 18:04
  • 3
    @Random832 Sharpies are not technically food safe, but, since you aren't eating the shell, it doesn't matter. The shell will protect the egg against any "toxins" that the sharpie could possibly introduce.
    – Nick2253
    Commented Feb 19, 2015 at 23:13
  • 7
    Egg shells are very porous, especially after boiling, so I wouldn't recommend using anything toxic on them.
    – Mark
    Commented Feb 20, 2015 at 11:53
  • 3
    Visibly porous—if you ever colour eggs for easter, you’ll find that the colour dissipates through the shell. Commented Feb 22, 2015 at 13:07

6 Answers 6


What's with all those complicated answers? There's a very easy way to check, one that I always use when I don't know if an egg is boiled or not:

Simply put the egg on a flat surface and spin it fast. If it's boiled, it will continue spinning, otherwise it will stop in 1-2 seconds.

EDIT: As Peteris suggested in his comment, basically a boiled egg will behave as a solid object. So, try to spin your egg 5 full rotations in one push. If you can't make it, it's not boiled.

  • 4
    And if people are confused about "did it stop quickly or not", then the intuition is that a boiled egg behaves exactly in a way that you'd expect a solid object to behave and a raw egg, well, won't.
    – Peteris
    Commented Feb 19, 2015 at 19:44
  • 3
    Um this is precisely what "all those complicated answers" suggested, hours before you! Commented Feb 20, 2015 at 2:19
  • 1
    @LightnessRacesinOrbit I'm looking at the most voted answer and it does start with rotation, but it's based on "abruptly stop[ping] it with a finger" which I think is unnecessary. Like suggested, a boiled egg will rotate as if it were solid, while a raw egg will stop very quickly (1, maximum 2 full rotations). Commented Feb 20, 2015 at 8:53
  • 1
    Just a quick note: this only works with hard-boiled eggs. The question didn't specify whether the eggs were hard-boiled or soft-boiled. Commented Feb 20, 2015 at 15:15
  • 3
    Alternately start the egg spinning, then very quickly stop it and let go. The boiled egg will stop, the raw one will start spinning again due to the fluid inside not stopping when you stop the shell.
    – Jon Story
    Commented Feb 20, 2015 at 16:23

As a non cooked egg is fluid inside we can make use of the rotational energy stored there. Put an egg on your desk and rotate it fast (like a gyro). Then apruptly stop it with a finger, then release it again.

  1. Case egg was cooked:

    enter image description here

    The egg will immediately stop spinning

  2. Case egg was raw:

    enter image description here

    The fluid inside will continue rotation, hence making the egg start rotating again.

  • 1
    Abruptly stop it with a finger, then release it again, right?
    – Jasper
    Commented Feb 19, 2015 at 12:56
  • @Jasper: of course... my bad it all was there but only in my mind - thanks for this :)
    – Takkat
    Commented Feb 19, 2015 at 12:58
  • 1
    It works, but it could also spin right onto the floor if you're not careful.
    – Mooseman
    Commented Feb 19, 2015 at 13:05
  • 20
    @Mooseman: LOL - then you'd find out for sure...
    – Takkat
    Commented Feb 19, 2015 at 13:21
  • LOL this answer was posted first AND has awesome little gifs, but the above duplicate answer was selected and recieved just as many votes. This sounds like a discussion for Meta
    – J.Todd
    Commented Feb 22, 2015 at 17:23

Option 1) Put the egg in water. A raw egg will have a tiny stream of air bubbles.

Option 2) Shine a strong flashlight through it. A raw egg will show light all the way through.

Option 3) Spin it on its end. The sloshy innards of a raw egg will cause it to wobble and a cooked egg will spin smoothly.


Shake it in your hand. If you hear it sloshing around inside, it's not boiled.

For the future, you may also wish to store your eggs in a vault, where pranksters can not access them.

  • 7
    Not a good idea if you're trying to preserve the internal structure of the egg (draining off whites, etc).
    – corsiKa
    Commented Feb 19, 2015 at 22:24

Hold it up to a very bright light. If you can't see inside it's been cooked.

  • Why the downvote? This is a method used in egg packaging industry to check on the quality of the eggs.
    – Willeke
    Commented Feb 9, 2017 at 21:08

It's kind of difficult to make out with just the spinning thing unless you have something to compare with. A BETTER WAY : Give a good spin to the egg along the horizontal axis on a flat surface. If the egg orients itself along the vertical one during its motion, it qualifies as boiled. Simple.

  • Answer seems decently written, will not vote up or down since I don't know if this actually works (I reviewed this).
    – k-l
    Commented Feb 9, 2017 at 18:46

Not the answer you're looking for? Browse other questions tagged or ask your own question.