Sour cream should not sit out for longer than four hours in temperatures over 40 degrees Fahrenheit. Sour cream that has been left at room temperature for longer than the recommended amount of time should not be consumed.
Sour cream should always be stored in the refrigerator to help prevent spoilage. Typically, unopened sour cream can last up to two weeks when it is properly stored. Opened sour cream can last up to 10 days in the refrigerator when it is stored in an airtight container. Sour cream that has a bitter flavor, too much water or spots of mold should be discarded.