Hi
This is an old technique I used to play when I was little in the Boy Scouts, but now with my DSLR i`ve got impressed.
Basically the main idea is to let the alcohol inside the bottle vaporize, and then turn it on, so you can take the picture.
In the next days ill take more pictures with different bottles, I promise to upload.
Camera: Sony DSLR-A300
Exposure: 3
Aperture: f/5.6
Focal Length: 50 mm
ISO Speed: 800
Exposure Bias: 0 EV
Flash: Off