But, a word on oxygen. The device essentially pumps pure air (79 percent nitrogen, 20 percent oxygen) into the coffee rather than fuss with nitro cartridges. This is cool, but oxygen exposure is the known enemy of fresh-tasting coffee. After the nitro evaporated, side-by-side taste tests did show more flabby oxidation flavors in the nitro than the basic non-nitro.
But fresh off the machine, this doesn’t show up much. What you notice is bracing, fun bubbles that also add perceived sweetness. Those bubbles cover a lot of sins, building a dense head atop cold brew that looks for all the world like a well-poured Irish stout.
A WIRED editor, looking at a photo of Cumulus’ abundant nitro, jovially suspected chicanery. “I’d swear they used Guinness for the promo shots,” he wrote.
The espresso is likewise effervescent—endowed with a thick and genuine crema, formed through the pressure…
