The principle of a vacuum brewer was to heat water in a lower vessel until expansion forced the contents through a narrow tube into an upper vessel containing ground coffee. When the lower vessel was empty and sufficient brewing time had elapsed, the heat was removed and the resulting vacuum would draw the brewed coffee back through a strainer into the lower chamber, from which it could be decanted. The Bauhaus interpretation of this device can be seen in Gerhard Marcks' Sintrax coffee maker of 1925.
CR’s take: If you like the look of black stainless steel, you can add a hit of the trendy finish to your kitchen with the Bella Ultimate Elite Collection coffee maker. Appearance aside, this model brews a fresh pot in just 9 minutes and is graceful in action, earning strong ratings in our carafe handling tests. It offers programming, brew-strength control, a pause-and-serve feature, and auto-shutoff. Bella drip machines also received a Very Good rating for predicted reliability. At about $50, this affordable, attractive option won’t disappoint.
Because the coffee grounds remain in direct contact with the brewing water and the grounds are filtered from the water via a mesh instead of a paper filter, coffee brewed with the cafetiere captures more of the coffee's flavour and essential oils, which would become trapped in a traditional drip brew machine's paper filters. As with drip-brewed coffee, cafetiere coffee can be brewed to any strength by adjusting the amount of ground coffee which is brewed. If the used grounds remain in the drink after brewing, French pressed coffee left to stand can become "bitter", though this is an effect that many users of cafetiere consider beneficial. For a 1⁄2-litre (0.11 imp gal; 0.13 US gal) cafetiere, the contents are considered spoiled, by some reports, after around 20 minutes. Other approaches consider a brew period that may extend to hours as a method of superior production.
For many of us, the daily grind can't begin until we've had that first cup of piping hot coffee—so the right brewer is at the top of the list. The most basic coffee makers make at least a decent cup, but a little more money buys conveniences such as programmability, a thermal carafe to keep coffee hot longer, settings that let you adjust brew strength, and more.