Episode Details

The vacuum coffee maker, also called a siphon or vac pot, moves water with no pump and no moving parts. Heat under the sealed lower globe expands trapped air and turns some water into vapor, pushing the rest up a tube into the upper chamber before it ever reaches a rolling boil, so the coffee steeps at roughly 90 to 95 degrees Celsius. When the heat is removed, the vapor condenses, a partial vacuum forms, and the brew is pulled down through a filter, leaving a relatively dry dome of grounds on top. Holding the water aloft takes a pressure difference of only about 1.5 kilopascals, which the barista must keep in balance with steady heat.

Johann Nürnberg is generally credited with the first vacuum brewer in 1827, and by 1840 James Robert Napier's version was circulating as a parlor spectacle. The Bauhaus embraced the design: Gerhard Marcks's 1925 Sintrax used borosilicate laboratory glass to lay the mechanics bare. The episode then turns to the self-extinguishing Belgian balance brewer and to Japan and Taiwan, where the siphon kept its prestige while the West moved to percolators and drip machines.

• Paper filters give a crisp, tea-like cup, cloth lets oils through for a heavier body, and glass rods rely on the grounds as a filter bed.
• A moka pot sends water one way through a packed basket with brute force, while the siphon runs on a whisper of pressure.
• The Belgian brewer sits on a seesaw, and as its heated chamber empties it rises and releases a snuffer that puts out its own flame.
• Clean, sediment-free coffee was the draw in an era of percolators that boiled the same grounds over and over.
• In 2022 Tiger Corporation released the Siphonista, an electric siphon with durable resin chambers.