But a word about oxygen. The device essentially pumps clean air (79% nitrogen, 20% oxygen) into the coffee rather than bothering with nitro cartridges. That’s cool, but exposure to oxygen is the known enemy of fresh-tasting coffee. After the nitro evaporated, side-by-side taste tests showed more flabby oxidation flavors in the nitro than in the base non-nitro.
But fresh out of the machine, it’s not very noticeable. What you notice are invigorating, fun bubbles that also add a perceived sweetness. These bubbles cover many sins, forming a dense head atop a cold brew that looks for all the world like a well-poured Irish stout.
A WIRED editor, looking at a photo of Cumulus’ plentiful nitro, jovially suspects a chicanery. “I could swear they used Guinness in the promotional photos,” he wrote.
The espresso is also effervescent, with a thick, authentic crema, formed thanks to the pressure exerted by the device’s powerful compressor. It was the natural foam of the Cumulus espresso that led to my generously foam-covered martini—a result that eluded me with hot, iced espresso.
Hats off to cocktail consultant and educator Josh Seaburg of Virginia’s Citizen cocktail modelfor a great espresso martini recipe to try. For the record, it was 1.5 ounces of vodka, 0.75 ounces of coffee liqueur like Mr. Black, and half an ounce of simple syrup, mixed with an ounce of cold espresso. Mix, shake, pour. The device only produces double shots, so one capsule provides enough cold espresso for two cocktails.
Who is Cumulus for?
On the one hand, the Cumulus is an impressive piece of engineering, succeeding on several fronts where other device makers have failed.
But this isn’t a device for coffee snobs. It lends itself best to those who enjoy the convenience of a Keurig and aren’t too picky, or those who would naturally load their cold brew with milk and sugar or other flavors. Cumulus doubles down with flavored syrups ranging from Piloncillo Orange to Demerara Cinnamon.
Photography: Cumulus
