Place the Eggs in a Pot

Hard-boiled eggs make a great snack or addition to salads, sandwiches or wraps. Although boiling an egg may seem simple, it takes precise timing to yield a perfectly hard boiled egg with no cracks or unsightly green yolks.

Cooking eggs in batches will save time and effort. Hard boiled eggs can be stored in the refrigerator, unpeeled, for up to a week. Only cook as many eggs as you plan to eat within one week.

Choose the size of your pot based on how many eggs you will be cooking. For even heating, the eggs should be placed in a single layer on the bottom of the pot; do not stack the eggs. The pot must also hold enough water to cover the eggs by one inch.

Place the eggs in the bottom of the pot in a single layer. Because most people do not keep their eggs on the counter at room temperature, these instructions have been tailored to work with refrigerated eggs.

Cover the Eggs With Water

Cover the eggs with cold water. To ensure even heating, the water should cover the eggs by at least one inch.

Placing one tablespoon of vinegar in the water will help keep the whites from spilling out if the shell cracks but may also add a slight flavor. Salt has the same effect but will raise the boiling point of the water, which can lead to over cooking and green yolks.

If the eggs are heated properly, the shells should not crack.

Heat the Eggs

Place the pot over medium/high heat, without a lid and allow it to come to a rolling boil. Bringing the pot to a boil without a lid will slow down the heating process and reduce the likelihood of the shells cracking.

You may see streams of bubbles coming out of the eggs as they heat. This is caused by the pocket of air at the bottom of each egg which expands as it is heated. The expanding air will escape through the tiny pores in the egg's shell and appear as a trail or stream of bubbles.

If the eggs heat too quickly, the air will expand faster than it can escape and the pressure will cause the shell to crack open.

Bring to a Boil

Allow the pot to come to a full, rolling boil. A full boil is indicated by large, vigorous bubbles.

As soon as the pot reaches a full boil, remove it from the heat.

Cover the Pot

After removing the pot from the heat, place a lid on top and let it sit undisturbed. This is where your timing needs to be precise. If the eggs sit in the hot water too long, they will over cook and end up with a green yolk.

Extra large eggs will need 18 minutes to fully cook, large eggs need 15 minutes, and medium eggs need 12 minutes. Set a timer to prevent over or under cooking.

For soft-boiled eggs (runny yolks, solid whites), let the eggs sit for 5 minutes less than the time needed to hard cook the egg.

When the timer goes off, carefully remove the eggs from the pot with a spoon and place into a bowl full of ice and water. The ice bath will cool the eggs quickly and stop the cooking process. The ice water will also cause the egg to contract and pull away from the shell which will make it easier to peel. Let the eggs sit in the ice bath for at least 5 minutes.

If you live in a climate where tap water runs very cold, you can run cold water over the eggs for five minutes rather than preparing an ice bath.

To peel the egg, lightly tap the egg on a hard surface to crack the shell. Once the shell is cracked all the way around, it should easily peel away from the egg. Once the shell is removed, briefly rinse the egg under water to remove any small bits of shell that may still be attached.

Any eggs that you do not plan to eat immediately should be left unpeeled and refrigerated. Unpeeled hard-boiled eggs will stay good in the refrigerator for up to a week.