How to Boil an Egg - 2 Main Methods

There are two methods for boiling an egg, each with their advantages and disadvantages:

• Boil First: One can bring a pot of water to boiling point, then add the eggs. The disadvantage of this approach is that the eggs sometimes crack, resulting in some of the egg leaving the shell and sometime water entering the shell. Although the eggs will still cook fine, they don't look as pleasing to the eye. Also, having water leak out of your egg as you open it at the table isn't that nice. The reason the eggs crack is that the shell is put under pressure by the sudden change in temperature when it is removed from a cold fridge and immediately put into boiling water.
• Eggs First, then Boil. The second approach is to put the eggs and water into a pot, then bring the water to a boil. The advantage of this approach is that the eggs are less likely to crack, as the change in temperature is more gradual. The disadvantage is that timing how long the egg needs to cook can be more difficult due to two factors
  • The egg cooks not only when the water is boiling, but also as the water heats up to the boiling point. So one must time not only the amount of time that the egg is boiling, but also make an allowance for partial cooking as the water approached boiling point.
  • The amount of time that it takes for the water to boil varies (depending on the amount of water, type of pot, intensity of heat), so the amount that the egg cooks prior to the water boiling varies.

Consequently, the first method is somewhat simplier, but at a higher risk of cracked and leaking egg shells. If you place an egg on a spoon and lower it into the water (rather than just dropping it in), this risk is somewhat reduced.

For the second method (adding the eggs and then bringing to a boil), there are solutions to the timing issue:

• Bring the eggs to a boil quickly. The faster you bring the water to a boil, the less that the eggs will cook in the pre-boiling stage. To do this you should use a small pot rather than a big one, use just enough water to cover the eggs, put a lid on the pot (may want to remove once it gets to boiling) and set the stove top to maximum.
• Always boil in the same way. The amount of time it takes for the eggs to boil, and consequently the amount they cook during this time, depends on the above factors (choice of pot, amount of water, use of lid, intensity of heat). So, if you always boil them in the same way, you can simply reduce the cooking time accordingly. For example, if you find that an egg needs only 3 minutes once the water is boiling, then it will always be the same provide you bring the water to a boil in the same way.
• Subtract 30 seconds. In practice, the amount of cooking which an egg undergoes while the water heats to boiling point is somewhere around half a minute. So, simply boil half a minute less than if you were adding them to boiling water. The main exception to this is if it takes a long time to get the eggs to boil. For example, if you normally cook 4-6 eggs in a small pot, then the half-minute rule is fairly accurate. However, if for an Easter-egg hunt you then try to cook 50 eggs in a huge pot, the pre-boiling time will be longer and would need to be allowed for.

How long to boil an egg

The amount of time you should boil an egg depends mainly on how well-cooked you would like it:

• Very soft (white has just set, yolk is runny) - 3 minutes
• Moderately soft (white fully set, yolk is partly set) - 4 minutes
• Almost hard-boiled - 5 minutes
• Completely hard-boiled - 8 minutes
• If your eggs are extra large, add one minute.
• If you bring the pot to a boil with the eggs in it (rather than adding the eggs to an already boiling pot) then subtract half a minute.

Do not overcook eggs. An egg that has cooked too long will have a grey (or even black) yolk and the egg white will have a rubbery texture.

If you are hard-boiling an egg and not eating it immediately, remove it from the hot water and place it in cold water. Otherwise, the egg will continue to cook in its shell and can become overcooked.

Fresh eggs take slightly longer cooking times than older eggs. The reason for this is that the egg proteins change somewhat as the egg ages, with the result that the proteins in an older egg go firm with slightly less cooking. In practice, this is a minor factor.

Eggs also cook slower at high altitudes (on mountains) than at sea level. The reason for this is that water boils are a lower temperature at high altitudes, so the egg is actually being cooked at a lower temperature and thus takes longer. For example, at 5000 feet (1500 meters) you would need to double cooking times. However, at moderate elevations, the difference in cooking times is relatively small.

Avoid cracked eggs

Cold eggs are more likely to crack than warm ones. So, removing the eggs from the refrigerator an hour before you boil them reduces cracking.

Avoid dropping the eggs. Place them gently into the pot. This can be difficult when adding them to boiling water, so in this case you can use a spoon to gently add them to the pot without risk of burning yourself.

The boiling water moves the eggs around, which can crack the shells. To avoid this, use a pot just large enough for the eggs, so they don't have room to bounce around. In addtion, once the water reaches boiling, reduce the heat so that they cook at a slow boil (or simmer), as a rapid boil bounces them around too much.

Peeling hard boiled eggs

A number of recipes require hard boiled eggs with the shell removed. Here are some tips to removing the shell:

• The big end of the egg has an air pocket at the tip. This is the easiest place to break the shell (by tapping it against a hard surface) and start peeling off the shell.
• Holding the egg under the cold water tap will help to remove loose bits of shell.
• Fresh eggs are more difficult to peel as the shell does not separate easily from the white. Try to use eggs at least 5 days old (check the packing date, not the best before date) as they will peel easier.

Health Considerations

Eggs are an excellent and healthy source of protein and other nutrients. However, they are moderately high in cholesterol, so if you have a high cholesterol you should limit the number and frequency of eggs.

Eggs can also be infected with salmonella. If the egg is hard-boiled, the salmonella is killed but not neccessarily with soft-boiled eggs. Consequently, you should avoid giving soft-boiled eggs to vulnerable groups (the very young, the very old, pregnant women and people weakened by illness).

This article is provide as part of our How to Cook series, written to provide basic cooking skills.