Definition - What does Downstem mean?
In a bowl or pipe, the downstem connects the bowl to the bong or body of a cannabis bubbler pipe. It functions when the user inhales through the mouthpiece, which creates suction that pulls the smoke through the downstem section into the pipe or bong and then to the user.
With a bong or bubbler, the downstem connects the bowl filled with cannabis to the water-filled reservoir. As the smoke is pulled from the lit cannabis into the bowl, down through the downstem, and then into the bong water, it is cooled and creates a smoother, cleaner hit.
Hydrolife explains Downstem
The downstem, sometimes spelled as two words (down stem), is a small tube that lets the smoke from the burning cannabis material quickly travel from the bowl filled with burning weed to the base of the bong where it bubbles through the water and is then inhaled by the user. The smoke is not only cooled but filtered throughout the entire process.
Through the use of the downstem, the user can typically inhale more smoke without suffering from a scratchy throat or coughing. It is far easier on the lungs and throat than other cannabis smoking methods. The system is often favored by medical marijuana users. The downstem on a bubbler pipe works the same way as on a bong. However, it is smaller on a bubbler and can get clogged up easier than on a bong, but the function remains the same.