If we boil an egg which already has a crack on its shell before boiling, it will break and spread into the water. In many cases if we put an egg into hot water it will crack also. So, is there any safe method to boil an egg like that, or should it be fried or cooked in another way?

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    I would like to remind everybody that this question is on methods for boiling known-cracked eggs without making a mess. If you have methods for detecting cracks, please post at cooking.stackexchange.com/questions/22535. If you have methods for reducing the chance that a whole egg will crack during boiling, please post at cooking.stackexchange.com/questions/909. For theoretical explanations why an egg cracks during boiling, post at cooking.stackexchange.com/questions/63296.
    – rumtscho
    Nov 26, 2018 at 15:52
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    Is "safe" really the word you mean? I thought this question would be about food safety, but it seems to be more about cooking an egg without making a mess.
    – nasch
    Nov 26, 2018 at 18:31
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    This depends on how much of a crack you're talking about. I deliberately put small cracks in my eggs before hard boiling to make them easier to peel.
    – barbecue
    Nov 26, 2018 at 18:54

9 Answers 9


If an egg is already cracked then it will almost certainly split open when boiled, there's no way to avoid it, it would be best to cook them using another method. Be aware that once eggs are cracked they no longer have protection against microbes, if you don't know how long they have been cracked it may be best to throw them away.


I use Egglettes™ to boil my eggs. You simply crack the egg/s into a silicone cup and place it/them into boiling water. Without wishing to seem like a crappy infomercial (see below), I find it a heck of a lot easier to crack an egg into a cup than I find it to peel eggshells off of a soft-boiled egg.

Obviously it makes no difference if the egg has already sustained a recent crack (from being dropped onto the surface, for example) since you're removing the shell prior to cooking.

enter image description here


For the avoidance of doubt, I am in no way affiliated to Egglettes other than being a customer

  • Wow, you'd be able to poach the egg too with this method. Just add a bit of water/vinegar in? Pretty cool
    – insidesin
    Nov 27, 2018 at 4:32
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    Yup. And scrambled by topping up with milk and swirling them with a chopstick for ten seconds
    – Richard
    Nov 27, 2018 at 7:13
  • Ordering some now then I guess :P
    – insidesin
    Nov 27, 2018 at 7:35
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    Could you edit a clarification/disclaimer into your answer as to whether you are affiliated in any way with this tool? It's probably not really an issue, but this network has had issues with people advertising products without properly sharing affiliation, which is spam according to our rules. It's fine to specifically mention a product you have a stake in, but you need to be clear about affiliation. meta.stackoverflow.com/questions/260638/… has more information on our spam rules.
    – Nzall
    Nov 27, 2018 at 9:52
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    @Nzall - I am in no way affiliated with this product. Also, people don't generally refer to their own adverts as crappy if they work for the company
    – Richard
    Nov 27, 2018 at 10:19

You can choose to poach the egg.

The egg is cracked into a cup or bowl of any size, and then gently slid into a pan of water at approximately 75 Celsius (167 °F) and cooked until the egg white has mostly solidified, but the yolk remains soft. The "perfect" poached egg has a runny yolk, with a hardening crust and no raw white remaining.

I don't have any experience with this but I would imagine you could cook it until the yolk hardens along with the whites.

  • To be clear, one of the key differences is water temperature--the water should be hot but not boiling--this helps keep the egg together (or rather, boiling water makes the egg not stay together).. Nov 26, 2018 at 18:46
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    @user3067860 Yep, I think the "75 Celcius" covers that though. At any rate, my answer addresses the "or should it be fried or cooked in another way" segment of the question.
    – MonkeyZeus
    Nov 26, 2018 at 18:49
  • I just never use a thermometer for cooking eggs, I go by "boiling", "simmering", etc. No idea how hot 75 C is except it's between 74 C and 76 C. Nov 26, 2018 at 18:59
  • @user3067860 Thanks again. That too sounds like an option so feel free to post your own experience with non-poaching cooking techniques.
    – MonkeyZeus
    Nov 26, 2018 at 19:26
  • @MonkeyZeus I don't think you're answering the question here. The asker is aware that there are other ways of cooking eggs and isn't asking for suggestions of them. The question is (paraphrasing) "Can I hard boil it or am I going to have to do something else?" not "What's the best way of cooking an egg whose shell is cracked?" So the answer is either "Yes, you can hard boil it using technique XYZ" or "No, boiling it won't work so you'll have to do something else." Nov 27, 2018 at 11:24

Adding salt in the water helps as well. There are multiple theories on why this works.

  • Osmosis direction
  • The egg white will become solid when getting in contact with the salt water and basically it will close the crack again.
  • Boiling point difference
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    It's hard to believe that the sort of quantities of salt one uses in cooking would make any significant chemical change. This sounds a lot like people claiming that you put salt in the water when you boil food because it means the water boils hotter so the food cooks faster -- in fact, the change in boiling point is of the order of tenths of a degree, so makes essentially no difference. Nov 26, 2018 at 15:56
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    In my experience, this is exactly the correct answer. It doesn't matter if it's because of chemical changes, boiling point difference or osmosis direction or whatever, as long as it works.
    – user70874
    Nov 26, 2018 at 16:14
  • My personal experience is also more salt = less cracking. I admit, I use a lot of salt when I know my eggs are cracky batch. Not quantities of salt one uses normally. I don't pretend to know or understand why it works.
    – Mołot
    Nov 27, 2018 at 9:13
  • @Mołot OK, but this egg is already cracked. Nov 27, 2018 at 11:25
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    The answer has been edited since my first comment so, in more detail: 1. Increased salt in the water would cause a tiny fraction more water to leave the egg; what difference would that make? 2. The egg white will already become solid when it hits the boiling water -- egg white hardens at around 80C (176F) and the boiling water is already much hotter than that. 3. As I've already said, the increase in boiling point from salting the water is negligible: even if you add 60g (2oz) of salt per litre (quart) of water, the boiling point will only go up by about 0.5C (1F). Nov 27, 2018 at 18:37

You can boil cracked egg safely just use 2 table spoons of white vinegar. Put White vinegar in boiling water and then gently put the egg in the water and let it boil. Egg will not come out of its shell. You can also make egg poach.Click here to understand about egg poach


Believe it or not, you can put some Duct Tape (like gaffer tape - heavy tape) over the crack, and away you go.

(I'm not sure why anyone would bother with this - boiled eggs which have some white "poking out" are fine - but there you have it.)

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    Is duct tape food safe though?
    – wjandrea
    Nov 26, 2018 at 18:13
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    @wjandrea It's safe to bet is not. This advice is only useful for people cooking for show. But there are people who needs perfectly boiled eggs for photos etc, so maybe someone will benefit from this answer.
    – Mołot
    Nov 27, 2018 at 9:18
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    The duct tape will leach who-knows-what into the water and the egg. Unless you have information to the contrary, you should assume that duct tape is not food-safe, and boiled duct tape doubly so. Nov 27, 2018 at 11:29
  • Although duct tape is indeed certainly not food safe, I personally would risk it. Decent duct tape isn't water soluble (though I'm less sure about boiling water soluble). I'm actually pretty sure I've had duct tape in contact with foodstuff I later ate, and no ill effects. And anyways eggs generally don't absorb much of whatever is in the water. But yeah, I'd rather not recommend this for anybody else. Nov 27, 2018 at 16:17
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    @leftaroundabout It's pretty likely that at least some components of the glue will start floating around in the water, even if they're not formally "dissolved". Nov 27, 2018 at 18:31

It's possible to boil an egg with steam. This usually requires an additional device. The eggs are put upright and won't split open since they are not exposed directly to the hot water.

enter image description here

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    Does this work for eggs that are already cracked? And why would being exposed to hot water make an egg more likely to split? Nov 26, 2018 at 15:54
  • I have two devices like this and the directions specifically say you need to pierce the top of the egg with a needle (that is included). Sometimes if the hole is a little big or if the hole is cracked, there is a considerable amount of egg white material ejected from the egg. It still makes a good hardboiled egg, but it's not as pretty. A cracked egg would certainly expand into a weird shape (again, would probably taste fine).
    – JPhi1618
    Nov 26, 2018 at 16:02
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    When doing hardboiled eggs in a commercial steamer i have seen the same issue with eggs coming apart as with boiling water.
    – Summer
    Nov 26, 2018 at 19:48

If the egg's been cracked for a while, just throw it out. Even though the boiling process should kill anything growing in it, good sense says it's not worth the risk. If the egg gets small cracks when you put it in the water or while cooking, it's perfectly fine. In my experience, the heat will quickly make the outer layer of white solidify as it cooks, which will lock everything else inside, crack or no. The worst I've ever seen happen from cooking an egg that cracked early on is that little bits of white escape and get cooked in the water, giving it a cloudy look. I've eaten many eggs that cracked while cooking and never had any problems.

  • I wouldn't trust boiling the egg to sterilize it. The outer parts will get up to 100C but the inner parts won't -- the yolk can completely set at about 70C. Nov 27, 2018 at 11:28
  • @David Richerby I agree. Better to get a fresh one.
    – CMB
    Nov 27, 2018 at 17:29

You can "steam" the egg instead. use a separator/sieve to suspend the egg above the boiling water in the pan. It will take longer than boiling to completely cook the egg.

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