Abstract: A baby bottle nipple including a flexible nipple body, a nipple tip, and a valve. The flexible nipple body has a body wall. The nipple tip has a tip wall that is more rigid than the body wall, a lumen defined through the nipple tip, and an opening disposed at a distal end of the nipple tip, the opening in fluidic communication with the lumen. The valve is disposed within the lumen such that the valve is disposed between an interior of the nipple body and the opening, and the valve has a closed configuration and an open configuration. The valve has a threshold cracking pressure to regulate flow, such that a non-negligible pressure differential is required to urge the valve into the open configuration.