But, a word on oxygen. This device essentially pumps pure air (79 percent nitrogen, 20 percent oxygen) into the coffee instead of the problem with nitro cartridges. This is good, but exposure to oxygen is a known enemy of fresh-tasting coffee. After the nitro evaporated, side-by-side taste tests showed a more flabby oxidized flavor in the Nitro than in the original non-Nitro.
But fresh from the machine, it doesn't appear much. What you're seeing are strong, funky bubbles that also add perceived sweetness. Those bubbles cover up a multitude of sins, creating a dense head on top of the cold brew that looks for all the world like a well-brewed Irish stout.
A WIRED editor, seeing a photo of the abundant nitro in cumulus, cheerfully suspected fraud. “I swear they used Guinness for the promo shots,” he wrote.
The espresso is similarly dazzling – with a thick and authentic crema, created through the pressure applied by the device's powerful compressor. It was the Cumulus Espresso's own natural foam that led to my beautiful foam-topped martini – resulting in a cold, not hot espresso.
A strong tip to Virginia cocktail consultant and teacher Josh Seaberg. Model Citizen CocktailTry these ingredients for a good espresso martini recipe. For the record, it consisted of 1.5 ounces of vodka, 0.75 ounces of coffee liqueur such as Mister Black, and half an ounce of simple syrup, mixed with one ounce of cold brew espresso. Mix, stir, pour. The device only makes double shots, so one capsule provides enough chilled espresso for two cocktails.
What is cumulus for?
On the one hand, Cumulus is an impressive piece of engineering – one that succeeds on several fronts where other appliance makers have failed.
But this is not a device for coffee drinkers. It's best for people who value the convenience of the Keurig and aren't overly fussy, or who naturally prefer their cold brew with milk and sugar or other flavorings. Cumulus doubles up on this flavored syrup From orange Piloncillo to cinnamon Demerara.
Photograph: Cumulus