Of all the various and myriad ways with which to make coffee, perhaps the strangest, most arcane method is the vacuum pot. It is certainly the most visually striking. Run a Google image search for vacuum pot coffee makers, and you’ll see what I mean. They tend to resemble laboratory instruments for a Victorian-era alchemist. As you can see in the picture, the lower bulb holds the water and the upper section holds the coffee grounds. Between them is a glass tube with a cotton filter.
Not only do they look weird, the method by which they make the coffee is also unique. The vacuum pot exploits the relationship between temperature, pressure, and volume by heating the water, which boils into steam. The steam expands, pushing the water up through the tube and the filter, and into the upper section with the grounds. The water brews directly with the coffee grounds until you remove the heating element. Then the steam cools and creates a vacuum and the brewed coffee in the upper section is pulled back through the filter. This creates and audible sucking sound and leaves the grounds almost completely dry.
And the coffee tastes wonderful. It has a kick of strong flavor that’s hard to get with most other methods. It’s easy to make too strong, but properly brewed it almost tastes like an espresso.
Making coffee with a vacuum pot is a really fun experience. Lots of careful preparation and measurement brings back fond memories of Bunsen burners, redox equations, and tritation (well, not so much the redox equations). It rescues the daily chore of making coffee and transforms it into an archaic and pleasurable experience. Indeed, vacuum pots were among the first modern coffee makers, first introduced in the mid 1800’s.
However, it takes a long time, which means that it’s strictly a weekend ritual for me. Vacuum pots are also expensive and delicate, generally running around $50 a pop. A far cry from a $20 Target electric dripolator with all the bells and whistles.
It’s definitely not my primary coffee maker. That’s a trusty old French press, of course. But it’s great fun to use and show off and makes wonderful, strong coffee.