The present invention includes a baby bottle liner constructed and arranged to fit into a cavity of a baby bottle. The baby bottle liner includes a continuous, profiled, elongated reclosable fastener. The continuous, profiled, elongated reclosable fastener has a first continuous elongated profile strip and a second continuous elongated profile strip. The first continuous elongated profile strip and the second continuous elongated profile strip are dimensioned to provide an airtight and/or watertight seal upon interconnection thereof. The baby bottle liner further comprises an airtight and watertight side seal at each end of the reclosable fastener. Each side seal connects an end of the reclosable fastener to an inside surface of a front wall and an inside surface of a back wall of the liner. The invention also provides a baby bottle with a baby bottle liner and a kit for infant nursing that has a plurality of baby bottle liners. The baby bottle liner can be constructed from a microwavable plastic and also visually indicate that a predetermined safe temperature range has been reached.