A cap assembly including a self-sealing membrane that overlaps an opening to an interior of a container. The cap assembly further includes a cap having a cover portion that includes an annular wall that defines a central opening, and at least one evacuating opening located radially outward of the central opening. The cover portion defines a gap above the self-sealing membrane. The gap is configured to allow the self-sealing membrane to be at least partially displaced from the opening to allow fluid communication between the interior of the container and an outside atmosphere when a suction is applied to the cap.