Perfect Hard Boiled Eggs

How difficult can it be to make perfect hard boiled eggs? All you need is eggs and hot water, right? Well, not exactly. Of the many methods I have tried, some resulted in eggs that were impossible to peel. Others cracked in the pot. And sometimes the eggs were cooked either too much or too little. Here are a few things I learned over the years.

Fresh or aged eggs?

If you have never tried to peel a hard-cooked fresh egg, you’re in for a shock. The shell glues itself to the egg. So when you peel off the shell — bit by tiny bit — you often end up peeling off several layers of white, as well. The result is a ragged-looking egg.

So start with eggs that aren’t fresh from the nest. An egg that’s at least a week old is much easier to peel. Store-bought eggs peel easily because they’re usually more than a week old by the time you get them home.

Aged eggs peel easier for two reasons. One is that, in an aging egg, carbon dioxide gradually leaks out through the shell pores. The contents therefore become increasingly more alkaline, causing the membranes to loosen. The other reason is that, as the content contracts, it develops more wiggle room inside the shell.

But an egg that’s more than about 10 days old has a thinned white, displacing the yolk from the center. An off-center yolk doesn’t matter for egg salad. But it doesn’t look as nice as a centered yolk in an egg served sliced or deviled.

Pinprick the shells?

A hard boiled egg is easier to peel if you poke a tiny hole in the large end with a needle or tack before cooking it. But you run a fine line between pressing hard enough to poke a hole and pressing so hard the shell cracks.

Aside from ease of peeling, a slight advantage to pricking eggs destined to be deviled is that it lets air escape from the air cell. The cooked egg therefore has a pleasant rounded appearance. Without pricking, the air in the air cell expands as the egg heats up, pressing against the large end of the egg and causing it to flatten.

Water to cover?

The pot you use should hold enough water to cover all the eggs by at least an inch. And the eggs should lie in a single layer at the bottom of the pot, preferably with plenty of room between them.

That means if you’re cooking a dozen eggs, you’ll need a bigger pot than if you were cooking just three or four. Having the eggs in a single layer ensures that your perfect hard boiled eggs cook evenly.

Cold or hot water?

Some recipes call for putting cold eggs in cold water and then bringing up the temperature. But this technique takes longer and makes accurate timing more difficult.

First heating the water to a rolling boil over high heat brings the temperature up faster and makes timing more accurate for correct doneness. It also makes the eggs easier to peel.

Plus you can cook both soft and hard boiled eggs at the same time. Just remove the soft boiled eggs after 5 minutes and let the rest cook the full time.

Cold or warm eggs?

Taking the eggs out of the fridge long enough to bring them to room temperature will reduce the chance of cracking when cold eggs meet hot water. But if you reduce the heat before adding the eggs, you can safely move the eggs directly from the refrigerator into the hot water. And the temperature shock resulting from putting cold eggs in hot water helps make the eggs easier to peel.

Be sure to lower the eggs gently. Whether the eggs are warm or cold, they’ll crack if they are summarily dropped into the pot. I use a slotted skimmer spoon to slowly introduce the eggs to the hot water.

Boil the eggs?

Boiled eggs should really be called “hard cooked eggs,” because they shouldn’t actually be boiled. Egg white consists of 90% water. The rest is a combination of proteins. Cooking eggs at too high a temperature creates extra bonds among the proteins, which forces out some of the water and makes the eggs tough and rubbery.

Boiling the eggs has another adverse effect. Letting the water boil causes the eggs to bounce around, and some of them will crack.

Therefore, once the water has boiled, reduce the heat before adding the eggs. Then adjust the heat to keep the water just at a simmer.

Salt the water, or not?

Some folks claim that salting the water makes eggs easier to peel. But it really makes no difference in peeling.

However, it can make a difference if an egg cracks. Salt water solidifies egg white more quickly. Therefore, if an egg does crack in the pot, the salt water will solidify the white to prevent it from leaking out into the water.

Lid on or off?

Cooks who prefer to start eggs in cold water, then bring the water to a boil in an uncovered pot, turn off the heat, cover the pot, and let it sit for a specified period of time. For various reasons, this technique doesn’t always result in perfect hard boiled eggs.

Directions for starting with hot water often don’t specify whether the lid should be on or off the pot. Leaving the lid on while the water is heating makes it boil sooner.

Depending on your cooktop, maintaining a simmer in a covered pot can be difficult while the eggs are cooking, unless you have a glass lid. I don’t, therefore I leave the lid off so I can monitor more easily.

How much time?

If you like your yolks well cooked, go for 12 minutes. For slightly soft yolks, 10 minutes. For fully cooked, crumbly yolks, 14 minutes. In 14-minute eggs the yolks are easy to separate from the whites, making them best for deviled eggs.

This timing is for large eggs. If you are using either smaller or larger eggs, adjust the timing a bit until the eggs turn out the way you like them.

But note that cooking eggs too long results in tough, rubbery whites and a greenish layer around the yolks. The latter happens because egg yolks contain iron, while egg whites contain sulfur. In the presence of heat, the iron and sulfur mix to make green-gray iron sulfide. Longer cooking time results in more iron sulfide.

Why fast cool-down?

To avoid overcooking eggs beyond the desired doneness, plunge them in cold water. Also, the temperature shock of rapidly moving the eggs from hot to cold water causes the egg white to contract and pull away from the shell membrane, making the eggs easier to peel. So as soon as the time is up, use the skimmer to remove the eggs from the pot and into a bowl of ice and water.

When you’re going to use the eggs right way, you can enhance peeling by gently cracking the shells before placing them in ice water. One common way to crack the shells is to pour off the hot water and shake the pot enough to make the eggs bump into each other. Skip this step if you plan to store the eggs to peel later.

Peel now or later?

If you wish, you can peel the eggs as soon as they are cool enough to handle. Immediate peeling has the advantage of reducing the nasty hydrogen sulfide odor temporarily emitted by hard-cooked eggs.

If you’re going to store them in the fridge to peel and use later, leave them in the ice water for about 15 minutes, until they are completely cool. I typically cook a dozen eggs at a time and store them, unpeeled, in a Lock & Lock egg carton. The Lock & Lock is air tight, therefore doesn’t allow the gassy hydrogen sulfide odor to permeate the refrigerator.

Best way to peel?

To peel a hard cooked egg, tap both ends on the counter, then evenly crack the shell by tapping it all over. Then roll the egg against on the counter or between your palms.

Sometimes the shell just falls away from the egg. If not, start peeling it off at the large end. Slipping a spoon between the egg and the shell at the large end can speed up peeling.

You can also speed things up by peeling the egg under cold running water. Whether or not you peel under a faucet, rinse off the peeled egg to remove any remaining crunchy shell bits.

In a nutshell (eggshell?):

To cook perfect hard boiled eggs:

• Start with a pot big enough for the eggs to lie in a single layer without touching.
• Fill the pot with enough water to cover the eggs by at least an inch.
• Bring the water to a rolling boil.
• Reduce the heat and carefully lower the eggs into the water.
• Adjust the heat to keep the water at a simmer.
• When the time is up, move the eggs to an ice water bath.
• Refrigerate in an air-tight container
• Store peeled eggs up to 1 week, eggs in the shell up to 2 weeks.

Timing Perfect Hard Boiled Eggs

10 minutes for softish yolks

12 minutes for firm yolks

14 minutes for crumbly yolks