To make hard-boiled eggs, put eggs in a single layer in a large, cold pan and cover with cold water that reaches 1 inch above the eggs. Bring the water to a boil. Remove the pan from heat, cover and let the eggs sit for 12 minutes.
The process for making hard-boiled eggs is the same no matter how many you cook at once. The pan should be large enough to hold all of the eggs in a single layer. The size of the eggs does affect cooking time. Medium eggs only need to sit for about 9 minutes, while extra large eggs need 15 minutes to fully cook. Eggs that are 7 to 10 days old often peel easier after they are boiled.
Drain the hot water from the eggs at the end of the cooking time. You can serve the eggs right away if you want warm eggs. Shake the eggs gently to crack the shells so they are easier to peel. If you prefer cold eggs, run cold water over the hard-boiled eggs or place them in a bowl of ice water.
Refrigerate any hard boiled eggs that aren't consumed right away. The eggs can be stored in an airtight container for up to three days.