Hard boiling an egg isn't difficult in theory: just boil some water, add your eggs, let them boil, and take them out. So why are hard-boiled eggs often so overdone that the that the yolks are chalky, or so underdone that the whites are almost runny? The answer is all in the timing and the temperature. Here's how you can cook a hard-boiled egg perfectly, consistently, every time you want one.
Photo by Craig Dugas.
The Traditional Method
The only things you'll really need to hard boil an egg are the eggs, a pot, water, and a timer. Boiling an egg isn't terribly difficult, but it is the reason the egg timer was invented. You'll need the timer at least until you've done it so often that you can just tell when the eggs are ready.
Place the eggs in the pot, but only add as many as can fit in one layer on the bottom. You don't want them rattling around or bouncing on top of one another when the water comes to a boil. Then fill the pot with water, covering the eggs with about an inch or so of water. Don't add too much water: if you add too much, it'll take too long for the water to come to a boil, and you'll wind up cooking your eggs longer as a result. Just give them enough water to cover them up and put the eggs on the stove. Photo by Robert Couse-Baker.
Add a pinch of salt to the water, and turn your stove on to a medium heat. Let the water come to a rolling boil. When you've got a good rolling boil, set your egg timer for one minute, and let the eggs boil. When the timer goes off, turn off the heat and move the pot to a cold burner. Set your egg timer for 15 minutes and walk away. It's important to use medium heat -- if you turn the heat up too high, you run the risk of cracking the eggs while you boil them, leaking egg white into the water while they cook. Keep the heat on medium and be patient.
This part is important: leave the eggs alone for the duration of the timer. They'll continue cooking in the hot water, and you don't need to continue to apply heat to let them cook through. If you've ever made hard boiled eggs and had them come out smelling sulphur-like, they're overcooked. Let the timer run out, and when it goes off, come back and test the water. If it's still warm but you can put your hand in it, the eggs are done and you can take them out.
Run the eggs under cold water for a minute or two before attempting to peel them. When you do, you should have a perfectly cooked hard boiled egg. When you peel the egg, the yolk should be evenly coloured (if it has a greenish skin or ring around it, it's overcooked) and should be dense but not chalky. The whites should be set and firm, but not rubbery. If you find they've overcooked, try turning the heat down a little bit, or removing them from the warm water sooner. Photo by Craig Dugas.
Bonus Tip: Boil Eggs in a Rice Cooker
This tip comes to us from reader TheFu, who noted that 25 minutes in the rice cooker with some water turned out perfectly hard boiled eggs each and every time for him. We looked into it, and sure enough it works. Just add enough tap water to cover the eggs (shouldn't be more than a tablespoon or two,) and turn in the rice cooker as though you're making rice.
The heat of the rice cooker and the wet paper towels will steam the eggs, and by the time the rice cooker cycle is complete, you'll have perfectly hard boiled eggs. You'll still want to run them under cold water to make them easier to peel. It's unorthodox, but it works and it's repeatable.
Cooking the perfect hard boiled egg is part art and part science. These steps will definitely work, but you may need to tweak them slightly based on the amount of heat your stove puts out at medium heat, or based on the size of the eggs you use. Even so, if you're looking for a delicious, hard boiled egg, this will get you there, and you can tweak the cooking times to get the consistency you prefer.
How do you cook your hard boiled eggs? Share your tips in the comments below.