According to a first aspect of the invention a can manufacturer completes manufacture of a can and then ships it to a filler, who needs only to fill the can with product. In a preferred embodiment the manufacturer pre-charges the container with a propellant. In accordance with a second aspect of the invention a desired quantity of gaseous propellant is first charged into a container, and a desired quantity of product is then injected into the container. A container filled in accordance with the invention maintains a predetermined pressure in the container as product is depleted from the container, and unacceptable pressure spikes are avoided as the container is being filled.