The quest of the perfectly boiled egg

[Major Nikon]

Last edited Sat Aug 10, 2013, 07:34 PM - Edit history (1)

Boiling an egg may be one of the simplest culinary chores, but believe it or not it can also get quite complex. If you're a big fan of scrambled eggs, you probably know that the best ones are made when the eggs come up to temperature slowly and evenly, which means low heat stirred often. The reason for this is because there are a few different proteins in the eggs which congeal at different temperatures.

There are two basic methods employed which are the soft and hard boiled eggs. The soft boiled egg is really just a reduction in time from the time required for the yolks to fully coagulate. The result is the yolks will be less firm than the whites due to the eggs cooking from the outside in. The biggest problem (at least for some) is that the whites tend to get rubbery from overcooking while the yolks are still undercooked. The quest for the perfect tender white and the perfect custard like yolk is never ending.

For centuries cooks have known that the best boiled egg is not boiled at all!

I love eggs and always keep a dozen in the refrigerator. Even though I seek out the best dates from the market when I buy my eggs, often I don't use them prior to their expiration date. Since I hate to throw out food and especially good sources of protein, I am always looking for uses for them prior to expiration. One easy solution is just to hard boil them, which effectively pasteurizes the eggs and extends their shelf life, but I don't particularly care for hard boiled eggs. Soft boiling them is a partial solution, but soft boiled eggs should be eaten right away unless you know for sure you have reached pasteurization temperature and time (more on this later). Sous vide eggs was a very interesting compromise for me. Pasteurization is a function of time AND temperature. So by cooking eggs for a longer time at a lower temperature you not only pasteurized them, but you also got something quite similar to soft boiled eggs. This presented it's own challenge. The egg yolk actually coagulates at lower temperatures than the whites. So in order to get custard like yolks, you were often left with runny whites (kind of the opposite of a soft boiled egg).

The good news is that you don't have to use boiling temperatures at all, and there's just a few things you need for countless experimentation. All you really need is a cooking vessel (I recommend a 7qt crock pot or a cast iron dutch oven), a thermometer, water, and eggs.

1) First a note on pasteurization. If you are reaching pasteurization time and temperatures, you can extend the shelf life of your eggs by a few days. So how do you know if you are there? Well a good rule of thumb is that if the yolk is not runny like a raw egg, even in the center, you have reached pasteurization. While it is possible to reach pasteurization with runny yolks, you know if you are beyond that stage, pasteurization has been achieved. You don't have to get to the firm yolk stage for this to happen. There are many custard like stages that happen prior to the yolk firming. All you are really looking for is that no part of the yolk is as runny as a raw egg.

2) Next a note on egg cracking. Eggs that are close to their expiration date will crack more readily than eggs which are fresh. What I do is prior to cooking I will soak my eggs in hot tap water for about 30 minutes or however longer it takes before I need them, replacing the water every 10 minutes or so. This brings the eggs from refrigerator temperatures to well above room temperature in the middle. If you have a problem with eggs cracking, absent rough handling getting them into the water bath the biggest culprit is temperature shock. The expanding gasses inside the egg can only escape via the egg pores and if they try to escape too quickly, the egg will crack.

3) The basic idea here is that you are going to use a temperature that begins at something less than boiling, then you are going to put the eggs in and turn off the heat. You will then allow the eggs to cook with just the residual heat contained in the water and cooking vessel. By varying the starting temperature, and the time the eggs are in the water bath, you can vary the consistency of both the yolk and the whites. Higher temperatures and faster cooking times will result in whites that are more dense and yolks that are less dense. Lower temperatures and longer cooking times will result in yolks that are more dense and whites that are less dense.

First I will describe a basic method using a 7qt crock pot (which I recommend). A 7qt crock will do a dozen eggs quite nicely. Fill the crock pot half full with a combination of boiling water and tap water until you get to 20F below your target temperature. For instance, if your target temperature is 170F, you will want your water temperature to be 150F. Turn the crock pot on high until your target temperature is reached. This will take about 30 minutes or more, which gives you time to perform the procedure listed in paragraph 2.

When the water in your crock gets to your target temperature, gently put the eggs into the water bath and turn off the crock. Put the lid on and allow to rest for your target time. If you like firm yolks and whites, I suggest going with a target temperature of 170F and a time of 30 minutes. If you like a consistency that is less firm for either the whites or the yolks, vary the two parameters per paragraph 3.

After your target time has been reached, take one of the eggs out and try one. If the eggs are ready, take them out of the water bath and rinse them off in cold water for a few minutes before refrigerating. This will arrest the cooking process.

Edited to add subsequent posts:

Here's another variation from the basic method:
If you follow the link I provided previously, there's a pretty handy chart which shows the coagulation level of the proteins in the white and yolk.

• 144F White: Begins to set, runny [font color="orange"]Yolk[/font]: Liquid
  
• 147F White: Partly set, runny [font color="orange"]Yolk[/font]: Begins to set
  
• 151F White: Largely set, still runny [font color="orange"]Yolk[/font]: Soft solid
  
• 158F White: Tender solid [font color="orange"]Yolk[/font]: Soft solid, waxy
  
• 176F White: Firm [font color="orange"]Yolk[/font]: Firm
  
• 194F White: Rubbery solid [font color="orange"]Yolk[/font]: Crumbly texture
  

The first thing you do is pick a consistency level for your yolk on the right. It will not be possible to get a consistency level for the white to be less than this point on the chart, however you can go the other way. If you want a yolk that is just beginning to set and a tender solid for the white, what you would need to do is hold 147F for a period of time(10 minutes or so), then raise the temperature to 158F.

Depending on your cooking vessel, this will take a bit of experimentation. For a 7 qt crock the temperature will drop about 8-10F when you put a dozen eggs in(provided they are room temperature or higher). So you would heat the water to 157F, put the eggs in, wait about 10 minutes, add some boiling water till the temp gets to 158F and then let the eggs sit in the water bath for about 5 more minutes or so.

Here's a trick regarding temperature measurement:
I remove the knob from the lid for my 7qt crock pot. This gives me a hole to insert my temperature probe. So I can make temperature readings without having to hold the lid off. I record the temperature every 5 minutes so I can make a simple temperature profile in my cooking journal.

[Phentex]

1. I am too lazy for perfection so I just follow Martha Stewart...

bring eggs to a boil, cover, remove from heat, wait 10 minutes. Done. No green. No soft yolk.

I can't say I've ever had an issue cracking an egg. Have you?

Or do you mean peeling?

[Major Nikon]

2. I mean eggs cracking when you put them in the cooking vessel

This will be more or less of a problem depending on which eggs you buy and how fresh they are.

The method you are using is the same as the one I'm describing. Your start temperature is boiling and you're using a 10 minute dwell time. This results in a yolk with a custard like consistency which varies from the outside in and a somewhat rubbery firm outer white. By using lower staring temps and longer dwell times you can get a softer consistency in the whites and a more even custard like consistency from your yolks.

To change your method up, all you would have to do is wait 5 minutes (or more) between the time you turn the heat off and before you put the eggs in, then let them dwell in the water bath for an extra 5 minutes or more. Essentially it's the same method with different timing.

[MrMickeysMom]

22. Me too...

works each time.. I peel them without difficulty later.

[BainsBane]

3. I buy eggs in half dozens

So there is less spoilage.

[bitchkitty]

6. You put a lot of thought into boiling an egg, Major.

This is my method, and it's been foolproof so far:

Place eggs into saucepan and cover with cold water. Bring just to a boil over high heat, then remove the pan from the heat and cover it for 20 minutes. Voila! Perfectly cooked hardboiled egg, and the shell slips off easily.

[Major Nikon]

7. Here's one way to look at it

In regards to beef steak, very rare to very well done spans about a 50F temperature range. Most people prefer a doneness level somewhere between which spans an even more narrow range.

So why not apply the same thought process to egg doneness levels? The temperature range is not that much different. Both involve protein. Both have significant differences throughout an approximately 50F range.

[bitchkitty]

8. I guess I just didn't care about the process,

only the end result. I haven't eaten meat or eggs in quite a while. When I did, I always ordered my steak "black and pink" - the cooks always seemed to get it right.

I myself have always been a horrible steak chef! So maybe I should have put a little more thought into it.

[sir pball]

11. To be fair

Grilling a steak by hand (without fancy tools like circulators or meat thermometers) is the height of the art. I've only come to grips with it after a year of doing it professionally and I'd still rate myself fair to middling; I know a guy who does 4-600 a night and gets maybe two back a week. After 8 years.

[bitchkitty]

14. The grill cook at the restaurant

I worked for would poke the steak with her finger. She cooked them by touch, I guess. No complaints that I know of. Not my thing though - even when I was a meat eater, I did not like handling raw meat.

[A HERETIC I AM]

17. Not at all uncommon for grill cooks.

"The grill cook at the restaurant I worked for would poke the steak with her finger. She cooked them by touch, I guess."

Referred to as the "Rule of thumb" - seriously.

Hold your hand palm facing up with your fingers relaxed. Touch the meaty part at the base of your thumb. That's the softness for Rare. The further you go toward the portion directly under your pinky finger, the more done the meat.

In years past I cooked for the EAA chapter I was a member of. We did an open house at Page Field in Ft. Myers and I cooked up to 450 hamburgers. We would have a Christmas dinner as well and I would do up to 75 Ribeyes.

Never had one come back using the above method.

[sir pball]

18. The One True Way For Steak:

Actually it's the One True Way For (Almost) Everything - meat, fish, veggies, pretty much everything EXCEPT cake. That you paradoxically do by touch.

[bitchkitty]

19. ???

Looks like a fly swatter. Do tell - how does that work?

[sir pball]

20. It's a cake tester

Nothing more than a slender wire on a plastic handle. You slide it into the thickest part of the steak/chicken/fish, wait a few seconds, then hold it to your lip to literally feel the temperature inside the steak. Veggies, you just poke to make sure they're tender. It's the only way a self-respecting cook does it. Well, except for cakes.

[bitchkitty]

21. And if you have to test more than once,

you then stick the saliva-coated tester back into the meat? Or do you use a fresh one? Doesn't seem too sanitary to me! LOL

[Jenoch]

9. I realize your method allows for various cooking

temperatures and various doneness of the eggs, but I have a foolproof way to hard cook eggs with the additional benefit of the easiest to peel eggs ever.

The answer is not to cook them in water, but to steam them. I use a stockpot with a pasta strainer.

Put about 1-1/2 inches of water into the kettle and bring it up to boil. Meanwhile put a dozen eggs (or how many you wish to cook) into the pasta strainer portion of the kettle. When the water boils, reduce it to a simmer, put the eggs in the kettle and cover. Steam for 13 minutes or so, it depends on the size of the eggs and whether they are cold from the refrigerator or room temp. I use large eggs right out of the refrigerator.

Put water and ice into your kitchen sink. After 13 minutes or so, put the strainer with the eggs into the ice bath for 5 minutes. After they are cooled I put them on a kitchen towel on the cupboard to let them air dry for a few minutes, then back into the carton after they get marked with a Sharpie and into the refrigerator.

[sir pball]

10. 75.0˚C for 60 minutes, then either shock or reduce to 55˚C

Oh, you mean in boiling water? Who doesn't cook with an immersion circulator these days?

(Seriously though - hunt on eBay and you can find used industrial ones for $100-200. I paid $190 shipped for a Haake that holds to 0.01˚ C, 10x more precise than the $700 PolySci at Williams-Sonoma!)

[Major Nikon]

12. If I'm making a dozen eggs sous vide, I like to cook them at 151F

The whites will still be runny, but the yolks will have a custard consistency. I like to leave them this way for storage. That way I can just break open a couple of them in a bowl, add a bit of salt and pepper, then nuke them until they are warm. The runny whites will firm up a bit in the microwave and they will be quite nice when served.

[sir pball]

13. Man, I had to convert that to C

Cooking eggs I can only think in C. 66 is one degree up from the perfect poach. If you push it to 68 (154.4), the yolk ends up the consistency of playdoh. It's great for making little sculptures.

And just to be an utter pedant - circulating eggs is "low-temperature cooking", not "sous-vide"; they're never vac-packed

[Major Nikon]

15. All my temp measuring can go either way, but most in America prefer F

So that's what I go with for public consumption.

Yes, it's technically water bath cooking using sous vide apparatus, but sous-vide is pretty close. Doug Baldwin, who literally pioneered sous vide for the home market lists a recipe for "perfect eggs" in his sous-vide cookbook.

[sir pball]

16. All my circs are in C so I think in that metric for that purpose

Yet I think in F for all other cookery. It's odd.

<nerdrage>Eggs don't involve any sous vide equipment. SV is the bagging (French for "under vacuum&quot ; low-temperature cooking (i.e. circulation) is a completely separate technique that can be done perfectly adequately in a Ziploc bag or even "naked" - try dropping steaks into 55C duck fat for an hour and then searing them off on screaming hot cast iron. It's how we did them at L'Ecole and they were the most popular item on the menu by far</nerdrage>

[Tab]

23. To properly hardboil an egg...

You put them carefully in a pot of water (room temp is fine), set it to a boil. When the water reaches a boil, turn it off. Let the eggs sit and return to room temp before you extract them. This eliminates the grey/green ring in the egg - that's caused by uneven nitrogen distribution. Turning it off at boiling temp and allowing it to settle gradually continues to cook the egg and allow the nitrogen to redistribute.

[Purplehazed]

24. I think you are...

essentially controlling the temperature that the inside of the egg reaches by this method. This was the way that I was taught to hard boil and egg. Happily, you don't have to wait until the eggs come to room temp. After 12 or so minutes the eggs will be cooked and no green ring. But if you try this method with a ridiculously large pot and only a few eggs, you will get the green because the large amount of water will hold the heat and get the inside of the eggs hotter. I don't believe the green has anything to do with nitrogen.

From about.com "The green ring forms when you overheat the egg, causing hydrogen and sulfur in the egg white to react and form hydrogen sulfide gas. The hydrogen sulfide reacts with iron in the egg yolk to form a grayish-green compound where the white and yolk meet."

I learned an old restaurant trick years ago and have never put eggs into a pot of water since; steam the eggs. Simply put the eggs in a steamer basket over a small amount of boiling water. Steam for 12-14 minutes. This way you are precisely controlling the time that the eggs are being heated. The added bonus of this method is that the intense heat from the steam cooks that membrane between the shell and the white and the shells will slip right off. Never a half pulled apart egg again.

[Tab]

25. I don't think the eggs have to be at room temperature to start

But they do have to be at room temperature at the end, and you cut the heat off when it starts to boil. This allows it to gradually redistribute the nitrogen (not hydrogen) and avoid the gray/green. I usually move it off the burner so there's no residual heat. Trying to cut corners by sticking it in the fridge (although you didn't say this) probably circumvents the system. Overloading the boiling water let it overcook, but not defeat the redistribution. Honestly I don't bother doing a ridiculously large pot for only a few eggs. If you want to add an addendum to the technique, I'd say just "don't use a ridiculously large pot for only a few eggs".