The most precise way to boil an egg
No egg comes out exactly as planned. You start the timer a little late, you lift the egg out a little after the bell, the egg weighs a little more than you thought. So the useful question is not only how long to boil an egg, but which way of cooking it forgives those small errors best.
We compare six ways: an egg straight from the fridge or at room temperature, cooled afterwards in an ice bath, in water or in the air. Each time the egg is medium (58 g), cooked to a jammy yolk (66 °C at the centre) at sea level, and each table runs from the most forgiving way to the least.
15 seconds early or late
Take the egg out 15 seconds late and its yolk ends up warmer than 66 °C; take it out 15 seconds early and it ends up colder. By this much:
| Egg starts at | Cooled in | Boil for (58 g) | Yolk off by |
|---|---|---|---|
| Fridge | Air | 5:39 | ± 1.1 °C |
| Room temperature | Air | 4:34 | ± 1.1 °C |
| Room temperature | Water | 7:12 | ± 1.1 °C |
| Fridge | Water | 8:22 | ± 1.2 °C |
| Room temperature | Ice bath | 7:26 | ± 1.2 °C |
| Fridge | Ice bath | 8:36 | ± 1.2 °C |
Here the method barely matters: every way lands within ± 1.1 to ± 1.2 °C. A few seconds won't spoil an egg, whichever way you cook it.
5 grams lighter or heavier
Eggs sold as medium in the EU weigh anywhere from 53 to 63 g: our 58 g, give or take 5 g. Boil a 53 g or a 63 g egg for the 58 g time and the lighter egg ends up warmer, the heavier one colder. By this much:
| Egg starts at | Cooled in | Boil for (58 g) | 5 g changes the time by | Yolk off by |
|---|---|---|---|---|
| Room temperature | Air | 4:34 | 17 s (6%) | ± 1.3 °C |
| Fridge | Air | 5:39 | 20 s (6%) | ± 1.5 °C |
| Room temperature | Water | 7:12 | 24 s (6%) | ± 1.9 °C |
| Room temperature | Ice bath | 7:26 | 25 s (6%) | ± 2.0 °C |
| Fridge | Water | 8:22 | 28 s (6%) | ± 2.2 °C |
| Fridge | Ice bath | 8:36 | 29 s (6%) | ± 2.3 °C |
Here the method does matter. A room-temperature egg cooled in the air lands within ± 1.3 °C; a fridge-cold egg cooled in an ice bath misses by ± 2.3 °C. The reason: 5 g more egg needs about 6% more time whichever way you cook it, and that share of a long boil is more seconds than the same share of a short one.
What it means
- The weight matters more than the timer. Getting the weight 5 g wrong costs a fridge-cold egg cooled in an ice bath as much as being 29 seconds late. Choose the right size, or type the exact weight in Chef or Scientist mode.
- If you can't weigh your eggs, keep the boil short. A room-temperature egg, or cooling in the air, forgives a wrong guess best.
- The cooling also shapes the texture. Cooling in the air gives a more even yolk, an ice bath a firm rim around a jammy centre: see an even or a contrasting yolk.
- Other errors to watch. The water should be at a rolling boil when the egg goes in and the fridge's temperature should match what you entered. With air cooling the result also depends on how warm your kitchen is, because most of the cooking then happens on the counter.
Open the calculator: its timer counts to the second, for the boil and for the cooling.