The bottle closure comprises a generally cylindrical inner member adapted to be threadedly engaged on the outside of the neck of a bottle. The inner member has a central passage communicating with the neck of the bottle. An outer member is rotatably mounted on and around the inner member. The inner member includes a valve seat defining a fluid passage between the bottle and the outer member and being located within the neck of the bottle. The outer member includes a valve closure element adapted to close the fluid passage in a first annular position of the outer member on the inner member thereby to form a seal with the valve seat. The outer member, when moved to a second annular position relative to the inner member, opens the fluid passage, thereby to allow fluid in a bottle to flow through the closure.