Abstract: A storage cap having a storage compartment, an aperture on the storage compartment, a rupturable membrane covering the aperture, and a receiving groove that engages a bottle, holds a measured amount of a powdered, granulated, or other flowable form of food or drug and provides for quickly, easily, neatly, and completely dispensing the food or drug into a typical 16 oz. to 1.5 liter water bottle. A preferred embodiment of the storage cap is filled with powdered flavor concentrate, and the aperture and the receiving groove are covered with the rupturable membrane. To dispense the powdered concentrate into a bottle, the storage cap is placed with the receiving groove facing the bottle neck lip. The storage cap is then pushed against the lip which urges the rupturable membrane into the groove. As the rupturable membrane is urged into the groove, the rupturable membrane is ruptured thus allowing the concentrate, but not the rupturable membrane, to flow into the bottle.