Hard-boiled eggs

• 12 wholelarge eggs · ideally 7 to 10 days old, straight from the fridge
• 4 quartswater · enough to cover the eggs by at least an inch once they are in
• 1 tbspkosher salt · optional, it seasons any cracks and makes the whites set faster
• 1 tbspdistilled white vinegar · optional, it coagulates leaking white if a shell cracks
• 4 cupsice · for the ice bath, and use more than you think you need
• 1 tspflaky salt · to finish, if you are eating them plain

Method

1. 1

   Start with boiling water, not cold water, and this is the whole trick

   The cold-water start you learned from a cookbook is the single biggest cause of eggs that refuse to peel. Bringing eggs up slowly from cold gives the white a long window in which it bonds to the inner shell membrane. Lowering a cold egg into water that is already at a rolling boil hits the outer white with instant heat, it sets and contracts away from the membrane, and the shell comes off in two or three pieces. Same egg, same pot, entirely different outcome.

2. 2

   The timings, by yolk, at a bare simmer

   From a hard boil, lowered in cold from the fridge, then held at a bare simmer: six minutes gives a set white and a liquid orange yolk. Seven and a half is jammy at the centre. Nine is creamy and fudgy all the way through, which is the one most people actually want when they say hard-boiled. Eleven is fully firm with no grey ring. Thirteen and beyond is where the sulphur smell and the green edge arrive. Set an actual timer, because ninety seconds is the difference between two of these.

3. 3

   Drop the heat to a bare simmer the moment the eggs go in

   A rolling boil for eleven minutes bangs the eggs against each other and the pot, cracks shells and gives you streamers of white in the water. Get the water to a full boil, lower the eggs in on a spider or a slotted spoon, then immediately turn the heat down until the surface is barely moving with a few bubbles breaking. The water is still around 200F, which is more than enough to cook an egg, and nothing is being knocked about.

4. 4

   Lower them in, do not drop them

   Use a spider strainer, a slotted spoon or a wire basket and take four seconds per egg. Dropping cold eggs into boiling water from a height cracks perhaps one in six, and a cracked egg leaks white in feathery clouds and comes out with a dented flat side. If one does crack, the tablespoon of vinegar in the water makes the escaping white coagulate almost instantly and seals it, which is the only reason vinegar is on the ingredient list.

5. 5

   Buy the eggs a week before you plan to boil them

   The pH of egg white rises as the egg ages, carbon dioxide escapes through the porous shell, and the bond between the white and the inner membrane weakens. Eggs at seven to ten days old peel cleanly. Eggs bought at a farmers market two days after laying will fight you no matter what technique you use, and no amount of baking soda or vinegar fixes it. Keep the very fresh ones for frying and poaching, where the tight white is an advantage, and boil the older carton.

6. 6

   The ice bath is not optional and five minutes is not enough

   Move the eggs straight from the pot into a bowl with as much ice as water, and leave them fifteen minutes. Two things happen. Cooking stops dead, which is what prevents the grey-green iron sulphide ring at the edge of the yolk. And the contents contract faster than the shell does, which pulls the white away from the membrane and creates the small air gap you need to get a thumb under. A five-minute bath on a warm egg gets you halfway and it shows.

7. 7

   Crack the fat end first, then roll

   The air cell sits at the wide end, so tapping there gives you an entry point with no white attached to the shell. Crack it, then roll the whole egg firmly on the counter under your palm until the shell is crazed all over like a windscreen. Get a thumb under the membrane at the fat end and the shell lifts in sheets. Peeling under a thin run of cold water helps the membrane release, and it also washes away the fragments you would otherwise chase around the bowl.

8. 8

   Steaming, when you want the method that almost never fails

   An inch of water, a steamer basket, lid on, twelve minutes for fully set. Steam is gentler than agitating water so fewer shells crack, the eggs never touch a boiling pot floor, and the peel rate is as good as the boiling-water start. It is also the method that scales best, because a steamer basket holds a dozen eggs in a single layer without them fighting for space. Add ninety seconds if you are cooking a full dozen straight from the fridge.

9. 9

   Altitude, egg size and the two adjustments nobody mentions

   Water boils cooler as you go up, so above about 3,000 feet add roughly a minute to every timing here, and above 6,000 feet add two. Egg size matters almost as much: a jumbo egg needs about a minute more than a large, and a medium about a minute less. If you cook the same eggs in the same pot every week, run the eleven-minute version once, cut one open, and write the number that worked on the inside of a cupboard door.

10. 10

    The grey ring, and why it means you overcooked them

    Sulphur from the white and iron from the yolk meet at the boundary under prolonged heat and form ferrous sulphide, which is the green-grey ring and the eggy smell that goes with it. It is harmless and it tastes chalky. It is entirely a time-and-temperature problem, so the fix is to shorten the cook and shock the eggs immediately rather than to change anything you buy. If you see it at eleven minutes, your simmer is closer to a boil than you think.

11. 11

    Storage, in the shell and out of it

    In the shell, refrigerated, hard-cooked eggs keep one week and no longer, which is much shorter than a raw egg because boiling strips the protective bloom off the shell. Peeled, they keep about five days in a sealed container with a damp paper towel over them to stop the whites going rubbery. Do not store peeled eggs submerged in water, which waterlogs them. Never leave cooked eggs at room temperature for more than two hours.

12. 12

    What to do with twelve of them, since you are here

    Two eggs is 13g of protein for around 145 calories, which makes a boiled egg the most efficient high-protein snack in the fridge and the reason this is a meal prep staple. Halve them over greens with a mustard vinaigrette, mash with Greek yogurt instead of mayonnaise for an egg salad, drop a jammy one into a bowl of lentils, or turn six of them into deviled eggs. Season with flaky salt at the moment you eat them, never in advance, because salt draws water out of a cut white.