The exact answer to the question “How long does an unopened package of sour cream last?” depends to a large extent on storage conditions — 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 40° Fahrenheit at all times.
How long does sour cream last at room temperature? If kept at temperatures above 40 °F, sour cream will rapidly develop signs of spoilage; sour cream should be discarded if left for more than 4 hours at room temperature.
How to tell if sour cream is bad? If sour cream develops an off odor, flavor or appearance, it should be discarded; if mold appears, discard the entire package.
Sources: For details about data sources used for food storage information, please