Transubstantiation is when djinn turn into smoke when they enter or leave a container. This way, they are able to enter and leave in any hollow object as they please. Most commonly, it is used for a djinn's lamp where they can reside and fill with their own belongings.
This process occurs when the heat from a djinn body's ignites with the oxygen in the air giving the illusion of smoke. When a djinn enters a container they must enter counter-clockwise if they are in the northern hemisphere; because when they enter the container time is different for they step outside the third dimension.
Space in a bottle to a djinn is very much like a room in a house for which they still retain djinn power and are able to make their stay comfortable for themselves. Because djinn are outside the third dimension, time is different inside the bottle, to a djinn an hour in a bottle is similar to ten hours outside the bottle. However, if a djinn enters the container the wrong way the opposite effect happens, in which 15 minutes outside the bottle may feel like three days in the bottle.