(57) A disposable package (1) for storing and transporting a liquid or viscous product such as for instance chocolate concentrate, and for dispensing said product in portions through a dispenser. This package comprises a rigid and load bearing outer cover (2), a flexible and tight bag (3) situated within said cover, and a stub (4) provided with a valve system (5). This valve system includes a cap-shaped body (17) of a flexible material, preferably rubber or plastics, and being connectable to a filling opening (27) in the dispenser (25). After a local cutting up of this body it forms a nozzle (17). The packed product can be dispensed from the inner bag (3) through the nozzle when the package is positioned in the dispenser (25) in such a manner that the nozzle (17) engages the filling opening (27) correctly. The nozzle (17) closes automatically when subjected to atmospheric pressure and opens when subjected to a low pressure in the filling opening (27) of the dispenser (25). Consequently, the product is dispensable in portions and possesses simultaneously a long storability in said package. Furthermore, the disposable package is easier and more hygienic to use in the dispenser than previously known, and the waste at the emptying is minimized.