For five minutes, water dribbles through a shower filter into a thick, tamped coffee puck, working its way slowly through the puck but releasing very few drops. Only when I start hand-pumping is the water pushed more quickly through the puck, dribbling out over the course of another minute or so: The air in the chamber reaches higher than one bar, about double what you’d usually expect from an AeroPress but still way less than the nine bars needed to qualify as espresso.
The resulting cold brew concentrate benefits from pressurized extraction, sure. But also, super-fine grounds aid faster extraction. Using a boatload of coffee grounds also means a greater bulk of flavor compounds is extracted.
The device manages to coax out a surprising amount of sweetness, especially with roasts that lean caramelly and medium-dark. And in such a short time span, it produces a satisfyingly full-bodied and full-flavored drink, ready to be diluted with ice or milk. In side-by-side testing, the results were significantly better than fast cold brew made with an AeroPress.
Some Don’t Like It Hot
But a lot of caveats are in order.
Is the cold brew produced by the Rapid Brewer as complex and sweet and smooth as a 12-hour cold brew? No, it’s absolutely not. The Rapid Brewer is a fast but blunt instrument, extracting sweetness and full body but not quite all of the flavor. And using the right roast matters a lot. While my first attempt with the brewer yielded cold brew so delicious I thought my senses had gone haywire, subsequent attempts with different beans showed limitations.
Light roasts, in particular, came out underextracted to the point of sour: don’t go below medium with this one. Too dark, you risk some bitterness. This really is a somewhat finicky balance you’re striking. (For the record, my initial success came with a medium-roasted Stumptown Colombia single-origin: have fun.)
You’re also using a whole heck of a lot of beans for each mug of cold brew: 40 grams of coffee for four ounces of concentrate, enough to make eight to 12 ounces of drinking-strength cold brew once diluted. By comparison, I’d expect to use less than half that if making 10-ounce mug of drip coffee. The portion you’re using for the Rapid Brewer is also significantly more than you’d need to make the traditional cold brew that involves patience and forethought.
Photograph: Matthew Korfhage
