Abstract: A bottle with a two position cap for sealing and venting the bottle. The bottle has an opening defined by a neck and the neck has external helix threads. The threads are divided into two threaded segments separated by two diametrically opposed unthreaded regions. Each of these threaded segments lies between large ribs on the neck and the bottle opening. The large ribs extend half way around the external surface of the neck. Indexing ribs extend axially on the neck. The bottle cap has internal helix threads that also are divided into two threaded segments separated by two diametrically opposed unthreaded regions as on the neck of the bottle. A pair of spherical detents on the cap lie between each threaded segment and the open end of the cap such that each pair of detents may snap over one of the large ribs on the neck with a detent on each side of an indexing rib to loosely hold the cap on the bottle and indicate that the cap is in a venting position.