How to siphon coffee Coffee with a side of physics sound good? You need a siphon – a.k.a. a vacuum coffee-maker – stat. While it doesn’t offer the pack-up-and-go convenience of an Aeropress, it does make for a theatrical coffee making ritual, and a well-balanced brew with body. Method Pour hot water into the bottom glass chamber or bulb. Sink the disc shaped filter and its attached chain by lowering it through the opening of the top chamber or hopper, securing the chain to the bottom of the funnel with a clip.Insert the top chamber into the bottom chamber, ensuring that the bulb is dry (moisture can cause cracking). Light the burner below it and turn the flame up high.While you’re waiting for the water to boil, measure out your ground coffee. When the water approaches boiling point, water vapour forces it into the top chamber.Turn down the flame of the burner. While there’s still a bit of water in the bottom chamber, add the coffee grounds to the top chamber.Stir the coffee grounds into the water until they’re completely saturated, then brew for 45 seconds to 1 minute. Extinguish the flame of the burner.Gravity pulls the coffee and water mixture through the filter, creating a vacuum, and the bulb fills with filtered coffee.