Egg quality deteriorates as much in a day at room temperature as in four days under refrigeration, and salmonella bacteria multiply much faster at room temperature. So it’s best to buy your eggs cold—out of the cooler, not off an open shelf—and keep them cold. Agitation thins the white, so an inner refrigerator shelf is preferable to the door. An airtight container is better than the standard loose carton at slowing moisture loss and the absorption of odors from other foods, although it accentuates the stale flavor that gradually develops in the eggs themselves. Bought fresh and treated with care, eggs should keep for several weeks in the shell. Once broken open, they’re far more susceptible to spoilage and should be used promptly or frozen.