rough-and-ready Exhibiting vigor and vitality which, though unrefined and perhaps indelicate, is appropriate for dealing with a given situation; crudely efficient; rough in manner, but prompt and effective in action.
1 The exact answer to the question âHow 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.
IF your fridge is quite cold and the cream has not been opened, it can be good for weeks past that date. Smell it. Rotten cream will stink. EDIT: lumps in cream is normal and can happen to totally fresh from the cow cream that is high in butter fat. If that happens, shake the cream to mix....