A liquid container (10) has a base (12) and a cap (14) which interengage to form a hermetically sealed chamber (42). The cap (14) has a curved outer wall (18) and the base has a curved inner wall (36). The outer and inner walls (18, 36) have perspective non-circular portions and are of complementary shape. The cap (14) is able to be rotated axially relative to the base (12) by means of a handle (24) so that the outer and inner curved walls (18, 36) interact such that the cap (14) is released from the base (12) upon axial rotation thereof and the hermetic seal is broken.