Put eggs into a pot (avoid aluminum as it will darken) and cover with cold water. Add a pinch of salt. Bring the pot to a boil over high or medium high heat, then lower the heat and simmer. Depending on the size of the eggs, they will need to simmer for 2 to 3 minutes for soft boiled, about 4 to 5 minutes for medium and 15 to 20 minutes for hard boiled. Drain the eggs and immerse them immediately in cold water to stop the cooking process. Refrigerated boiled eggs will keep for about a week.