A baby bottle device (100) is provided which comprises a container (110) with a container volume (115), a teat (120) with a teat volume (125) and a valve unit (200). The teat comprises a first valve (112) for inletting air into the inside volume of the bottle (100). The inside volume of the bottle corresponds to the volume of the container (110) and the teat volume (125). The valve unit (200) with a second valve (210 230) is arranged outside the teat volume (125). The threshold of the vent unit is lower than the threshold of the first vent (112) in the teat.