An insert for a multiple component container includes an upper seal member (10), a depending annular wall (22) sealed to the underside of the seal member (10), a depending spigot (20) connected to the underside of the seal member (10) and a movable wall (28; 60) carried by the depending wall (22). The seal member (10), the depending wall (22) and the movable wall (28; 60) define an interior space. The movable wall (28; 60) is movable with respect to the depending wall (22) under the action of a pressure within the interior space and affording a discharge aperture (32), within which the spigot (20) is slidingly and sealingly received. The interior space accommodates a movable piston member (8), which divides the interior space into a gas space (46) and an ingredient space (44) below it. The outer edge of the piston member (8) forms a sliding seal with the inner surface of the depending wall (22) and a hole is formed in the piston member in which the spigot (20) is slidingly and sealingly received. A gas supply pathway (34) communicates with the gas space (46) and is constructed to permit gas to flow from the exterior of the depending wall (22) into the gas space but substantially to prevent flow in the opposite direction.