how long can you keep cream in the refrigerator
1 The exact answer to the question âHow long does an unopened package of sour cream last?â depends to a large extent on storage conditions â to maximize the shelf life of sour cream, keep it refrigerated at all times.  How long does unopened sour cream last after the sell-by date? Sour cream will generally keep for one to two weeks after the sell-by date on the package, assuming it has been continuously refrigerated; be sure that the temperature of your refrigerator remains at or below 40Â° Fahrenheit at all times.