A portable beverage container (e.g., an insulated, double-walled bottle) is disclosed. The container includes a lid pivotably connected to it by a hinge. The lid is arranged to be automatically pivoted open by the spring assembly when a catch on the lid is released so that the lid opens in a controlled, non-jarring manner. The spring assembly comprises an elastomeric member and a contact surface (e.g., a recess in a cap of the bottle). The elastomeric member is arranged to cooperate with the contact surface whereupon the elastomeric member operates bi-modally to effect the automatic opening of the lid.