Like anyone on the planet, I hate the smell of rotten eggs. How can I tell if an egg is bad without cracking it open?

So far all I have tried is simply cracking it open and then throwing away the egg if it is bad, but that creates a bad smell and is a waste - I might be able to use some for cooking that I would otherwise throw away.

  • In regards to the edit: getting help on what to try would be where you would ask on Cooking.SE, getting help on something else to try would be where you would ask here. Dec 16, 2014 at 15:36
  • ... still seems like a scope issue. one of the "off chance cases" where listing what has been tried is difficult, yet the question is still valid.
    – Phlume
    Dec 16, 2014 at 15:39
  • 2
    That rant is not apropriate
    – Tim
    Dec 16, 2014 at 16:48

3 Answers 3


I place the egg in a glass of water.

If it floats, it is bad. If it stands up, use it for cooking (e.g. a hard boiled egg but not soft), it's getting old. If it sinks, you're safe.


The outer shell of an egg has two membranes under it. When an egg is laid, it is warm and starts cooling which contracts the inner part of the egg more than the shell and pulls the two membranes apart. As a result, air gets trapped in between the membranes (there is not enough air initially for it to float).


As this egg gets older, air is taken in (due to slightly higher pressure from the contractions) through pores in the egg. Eventually, bacteria will get in too. When the egg has enough air to float, it's probably gone bad with the bacteria.

4 egg positions

Image © Tim, 2014

  • I put my egg in some cold water and it came up as 'cooking'!
    – fredley
    Dec 10, 2014 at 21:12
  • 3
    If this is your image, that's really cool that you made it up for this answer. If not, some attribution would be nice :)
    – Shokhet
    Dec 10, 2014 at 21:34
  • 2
    +1 for the illustration of wrong! A of answer too, I guess!
    – liebs19
    Dec 11, 2014 at 1:04
  • 1
    I raise chickens - just a note on this technique - if you wash your farm-fresh, previously unwashed eggs, they must immediately go in the fridge, since you're washing away the outermost layer of what was once mucous... so the eggs start to dry out quicker and puf go bad. Otherwise they're good on the counter for a couple of weeks!
    – user1339
    Dec 17, 2014 at 0:18
  • 1
    Isn't that "wrong" just a poached egg?
    – Random832
    Apr 29, 2015 at 17:36

If you are in a situation where bringing water adds another burden to you, you can identify the quality of an egg by gently shaking it and hearing it. This works like a charm in me.

It states in the Source:

Take an egg from the refrigerator and hold it up to your ear. Shake it gently. If it's fresh, it won't make a sound. If it's on the older side, the egg will make a slight rattle.

But according to this source there is a warning here

Shaking an egg next to your ear to see (or rather hear) if it's rotten works without fail for me. Eggs that have gone bad make the characteristic sound of something splashing around inside the shell while fresh eggs make no sound at all.

For those not used to this method of detection, a word of caution might be in order. Do not hold the egg too tightly or shake too energetically. It is not that in case you do so you will fail to detect a rotten egg. Detection will be as easy or even easier in this case. However, there may be undesirable side effects.



Through this method, the approximate age of the eggs can be found. So We can be able to know how long can we keep and which egg to use first.

enter image description here

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