Siphon coffee, also called vacuum pot or syphon coffee, is one of the more visually striking ways to brew, and unlike most methods on this site, the physics behind it is genuinely worth understanding, because the brewing itself is entirely driven by vapor pressure rather than gravity or manual force.
The setup uses two glass chambers stacked vertically, connected by a tube with a filter at the bottom of the upper chamber. Water sits in the lower chamber, which is heated directly, by an alcohol burner, halogen beam heater, or gas burner depending on the specific device. As the water heats and approaches boiling, the resulting vapor pressure pushes the water up through the tube into the upper chamber, where the ground coffee is waiting.
Once most of the water has risen into the upper chamber, it mixes with the grounds and steeps, typically stirred once or twice during a roughly one-minute steep. When the heat source is removed, or in some designs simply lowered, the vapor in the lower chamber cools and contracts, creating a slight vacuum that pulls the brewed coffee back down through the filter into the now-empty lower chamber, leaving the spent grounds behind in the upper chamber.
The result is a cup often described as unusually clean and tea-like for a full-immersion method, closer in clarity to a pour-over than a French press, since a cloth or fine paper filter typically catches more sediment than a French press's metal mesh does, while the full immersion still extracts a fuller flavor than most pour-over methods manage.
Siphon brewing traces back to European design experiments in the 1830s and was refined into something closer to its modern form in the 19th and early 20th centuries, before becoming particularly associated with Japanese cafe culture in the 20th century, where meticulous, ceremony-like brewing methods found a receptive audience and the device became something of a signature presentation piece. Sprudge's brew guide compendium includes a siphon walkthrough if you want to see the sequence laid out step by step.
The honest tradeoff is that siphon brewing genuinely is more theater than most other methods, the open flame, the bubbling glass, and the dramatic vacuum-driven return of the coffee are part of the appeal, and a shop that offers it is usually leaning into that presentation as much as the resulting cup's actual flavor profile, which, while genuinely good, is not so dramatically different from a careful pour-over that the extra equipment and time are strictly necessary for flavor alone.
It is not a practical everyday home brewing method for most people, given the equipment cost, the direct flame, and the attention required throughout, but it is a genuinely fun one-off to try if you come across a shop or a friend who owns the setup, and a good entry point if you are curious about how far coffee brewing can be pushed as a deliberate, almost performative ritual rather than a quick morning routine. James Hoffmann has a good video on the siphon's history and mechanics if you want to understand it before hunting one down.