A mixing apparatus is for selective mixing of contents. The mixing apparatus has a body that defines an interior space. The body further has an aperture for permitting access to the interior space. The body has at least a portion that is collapsible and configured to be gripped and repositioned by a user to collapse a part of the body into the interior space to alter at least one of: the volume of the interior space; and the shape of the interior space. The mixing apparatus further has at least one mixing member located within the interior space that is configured and located so that the contents is forced against the at least one mixing member when the collapsible portion is gripped and repositioned by a user.