Note the color of the egg white. The cloudy appearance of an egg white actually indicates freshness, due to its higher carbon dioxide content. As the egg ages, the carbon dioxide escapes and the egg white becomes more transparent. Store eggs in the original carton in the refrigerator. Do not wash the shells, and do not store eggs on the door of your refrigerator; this exposes them to room temperature every time the refrigerator door is opened. Use hard-cooked eggs (in the shell or peeled) within one week after cooking. Cooked eggs, including hard-boiled eggs and egg-containing foods, should not sit at room temperature for more than two hours. Refrigerate leftover cooked egg dishes immediately, and save for no more than three to four days. Large portions should be divided into several shallow containers so they will cool quickly.