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Jul 28, 2011 10:08 AM

Gray Ring Around Yolk of Hard Boiled Eggs...

No matter how softly I boil eggs, *after* refrigerating them they always have a gray ring around the yolk. I heard somewhere that placing eggs in ice water after cooking prevents this (I rinse with cold water for 5 minutes). Have you found this to be true?

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  1. Has nothing to do with ice water and everything to do with (over)cooking. To hard "boil" eggs, place them in room temp water in a pot, bring to a boil and then cover and remove from heat. Wait 12-13 minutes and then rinse in cold water to stop the cooking. Yolks should be yellow all the way through.

    6 Replies
    1. re: ferret

      That gray ring is iron that leached out from overcooked yolks. Follow "ferret's" directions to get perfect boiled eggs.

      Link to another way to boil eggs:

      1. re: Norm Man

        I use the same process as ferret and seldom if every get the green rings.

        I rinse in cold water after cooking in a running water bath for 3- 5 minutes until cool to the touch then add ice and change out non-running cold water bath every 5 minutes or so until internal egg temps drops and stops cooking. Then right into the fridge.

        1. re: jjjrfoodie

          A nice big ice-water bath (with plenty of ice), and you won't have to run water or change water every 5 min. Eggs stop cooking and cool down quickly. In my experience.

        2. re: Norm Man

          Those are excellent directions and yet I find that even an egg that's never been overcooked can develop the gray ring over time so don't do more eggs at a time than you mean to use in 24-36 hours.

      2. The gray/greenish ring result from eggs not being cooled and/or overcooking.

        Typically, I boil eggs 7 to 8 minutes and cool immediately. No ring around the yolk.

        1. Why is a ring round the yolk a problem?
          It tastes the same to me - why make an effort to avoid it?

          8 Replies
          1. re: Peg

            It's not the grey ring itself which is the problem. It's that the grey ring is an indication that the yolk has been overcooked, and overcooked yolks are dry and crumbly.

            A properly cooked egg yolk will be bright yellow and *moist* all the way through. If you've never had a properly cooked egg yolk, you've probably resigned yourself to believing that overboiled egg yolks are the only way to make them, and it's simply not true.

            I have been using a method similar to ferret's with perfect results nearly every time, although I usually steep the eggs in boiled water for about 10-11 minutes and then plunge the eggs into an ice water bath. On very rare occasions the center of the eggs are a little underdone, but it doesn't bother me as I enjoy soft boiled eggs too.

            Mr Taster

            1. re: Mr Taster

              Ah - I have done them both ways (overcooked and not) and actually prefer the dry crumbly ones unless I'm aiming at a semi-liquid yolk.

              1. re: Peg

                >> unless I'm aiming at a semi-liquid yolk.

                Just to be clear, a properly cooked egg should not be semi-liquid, which would be undercooked (sorry if my example threw you off).

                A properly cooked yolk is a moist solid, as opposed to a dry, crumbly solid.

                Mr Taster

                1. re: Mr Taster

                  We make dozens of eggs each year for our Elks Family Picnic potato salad, and we never get the gray ring. One secret to easy peeling is to buy the eggs a week before you plan to boil them. (I do this each Easter, too.) I put them in a large pot, cover the eggs with water by about an extra inch or two, bring to a rolling boil, remove from heat and cover for 12 minutes. Then I put them in an ice water bath. Have no problems with rings, as this method really works. Learned this as a home economics major at Oregon State. Go Beavs!!!

              2. re: Mr Taster

                change your terminology, they are soft cooked and hard cooked eggs as Boiling is what causes the over cooking and the black ring around the yolk, this is what we learned to college food science classed!!!!!,

                1. re: BH.

                  But this isn't food science. It's an art.

                  People can enjoy their boiled eggs soft, hard, or at the wide grey area in the middle where the yolk is more soft than hard, or more hard than soft.

                  Mr Taster

                  1. re: Mr Taster

                    I think the point was that the eggs should not be boiled, but simmered.

                    1. re: John E.

                      Perhaps... I took my best guess at what BH. was trying to communicate.

                      Mr Taster

            2. True or not, I can't say, but what Jacques Pepin has to say about the dreaded ring is that it is caused by sulfur migrating to the coolest part of the egg during cooking, and that the way to prevent them is by promptly cracking the shell after dumping the cooking water, then putting the egg into ice-cold water. He says the sulfur migrates toward the now colder white, and escapes into the water through the cracks. He cracks the eggs by leaving them in the cooking pan while he pours out the hot water, then swishing the pan around until the eggs crack by smashing into each other and the sides of the pan. Then he fills with ice water.

              Don't shoot the messenger. I am just paraphrasing what he said on one of his TV shows and
              have almost always found his advice to be sound.

              14 Replies
              1. re: greygarious

                That sulfer migrating thing sounds like something Jacques learned as an apprentice in France in about 1950. I think the cracking the egg and placing it in cold water will make it easier to peel but the gray/green ring is from overcooking not from not allowing the sulfer to 'migrate'. The old time chefs (not necessarily Jacques) are the same people who claim there are male and female eggplant and other interesting tales.

                1. re: John E.

                  The sulfur reason was something I learned about in a cooking class.
                  Also, it's the same reason listed on the American Egg Board website...

                  In regards to make and female eggplants, Alton Brown mentions that male eggplants are better if you have older/more mature eggplants.

                  1. re: dave_c

                    Except that there is no such thing as 'male' and 'female' eggplants. An eggplant is a fruit without a gender.

                    1. re: John E.

                      There are indeed gender differences in fruits as a result of how they were pollinated. If you doubt it, read about the complicated sex life of figs.

                      As for the practical implications of this gender bias, the male fig is fibrous and entirely inedible whereas the female yields a juicy fruit.


                      As far as eggplants, one gender has quite a lot more seeds than the other, in addition to more subtle physical characteristics (a dimpled versus a flat blossom end, etc.)

                      If what you're really arguing is over the semantics of whether fruits explicitly possess sex organs in the way, I'll leave that for the botanists to discuss. Though I do remember a rather game changing lecture in my freshman biology class where my professor described a fruit (such as an apple) as a huge, overdeveloped ovary.

                      Mr Taster

                      1. re: Mr Taster

                        I did not say that there were not eggplants that have more seeds than other eggplants (I know virtually nothing of figs), I simy said that there is no such thing as a 'female' eggplant or a 'male' eggplant. You may call it semantics, I call it facts. The eggplants are the result of the flower on an eggplant plant being pollinated.

                        1. re: John E.

                          From a gardening class I took ages ago, I believe eggplants are self-fertile where an eggplant can grow from a male or female flower. Pollination helps ensure flower set and a good crop/better yield.

                          True or not? I never really questioned it.

                          1. re: John E.

                            I'm hardly an horticultural expert. But isn't every fruit the result of pollination? The pollen (sperm) from the male organs travels down the flower to the ovary, and the ovary grows into the fruit, whether it's apples or figs or eggplants.

                            If figs develop specific traits related to gender, then why is it so absurd to consider that eggplants could do the same? I'm asking sincerely. I really don't know the answer.

                            Mr Taster

                            1. re: Mr Taster

                              Figs are tricky. They do not have flowers in the normal sense nor are figs fruit. They are inflorescences. I don't claim to know everything there is to know about eggplants and I surely don't know everything about figs, but you also have not provided enough information to believe the resulting ''offspring' that we eat have a gender. I also don't need for you to provide such information because I am really not that interested in the subject.

                              1. re: John E.

                                > I also don't need for you to provide such information because I am really not that interested in the subject.

                                Fair enough. (Though for someone uninterested, you've replied an awful lot!)

                                Mr Taster

                                1. re: Mr Taster

                                  So . . .

                                  Even though eggplants look like gourds and are in the nightshade family with sexy tomatoes and evil jimson weed, eggplants can self pollinate? And if an eggplant self pollinates it changes the amount of seeds it produces? What benefit to the eggplant is producing the less seedy fruit? Is self-pollination some crazy last ditch effort on the plant's behalf?

                                  1. re: Mr Taster

                                    You kept asking me questions. Sometimes we (me) post things that are meant to be innocuous but generate a response that increases their importance far greater than intended. This is one of those instances.

                      2. re: John E.

                        Apparently JP is on solid scientific ground here after all! I just got the 1997 paperback edition of McGee's "On Food and Cooking". On p. 69, "The yolk contains a good deal of iron, and the albumen a good deal of sulfur, primarily in side chains on the protein ovalbumin. When that protein is heated, some of its sulfur atoms are liberated and react with hydrogen ions in the albumen to form hydrogen sulfide (H2S)...As the gas forms, it diffuses in all directions, and some reaches the surface of the yolk, where it encounters iron and reacts to form the dark particles of ferrous sulfide (FeS). The way to minimize the discoloration is to minimize the amount of hydrogen sulfide that reaches the yolk. First, cook the eggs only as long as necessary to set the yolk. Then plunge the cooked eggs immediately into cold water. This lowers the pressure of the gas in the outer regions of the white, since cool gases exert less pressure than hot, and cool protein loses less sulfur than hot. Consequently the hydrogen sulfide diffuses away from the yolk, toward the region of lower pressure at the surface. Finally, peel the eggs promptly: this also helps pull the gas away from the yolk."

                        1. re: greygarious

                          Interesting, thanks!

                          I never thought to peel my eggs right away...will be a hard habit to "break" :).

                          1. re: greygarious

                            You have written an interesting post, so it's still about overcooking the eggs?

                      3. Thanks mine are perfect when eaten before refrigerating.

                        The only thing I do differently from the video is add them to ice water after cooking (and I think she cracked them too--that's a new one for me, she & Jacques must be on to something there!)