How Science can impove the test of a Cold Brew

Posted on: 2015-04-06 12:00 AM

When Victor Vasquez, director of coffee for Dolcezza, first tasted the cold-brew java pulled from a new tap system at AC Beverage, he basically accused the Annapolis company of adding sugar to his drink.

“They showed me their [cold-brew] concentrate, and it had no sugar,” Vasquez recalls. “When they went through the system [to explain it], I was like, ‘Are you sure that doesn’t infuse sugar in it?’”
AC Beverage’s JoeTap system has no sugar added. But depending on the coffee and the amount of nitrogen and/or carbon dioxide infused into the liquid, JoeTap can make cold-brew coffee taste as if you’ve added cream and a sweetener to the cup. The system, which will debut April 9-12 at the annual Specialty Coffee Association of America Event in Seattle, is expected to push nitrogen-infused coffee — a fringe product known as “nitro coffee” among the hardcore caffeinated types — further into the joe-slurping mainstream.

Charles Kleinrichert, founder AC Beverage and inventor of JoeTap, expects to start selling 50 units a week once the specialty coffee hordes taste the nitro-infused mud from his proprietary system, which ranges in price from $4,350 to $4,750 per unit.  “We’ve got some tentative verbal orders,” Kleinrichert adds.

Dolcezza is an early adopter of the technology, despite founder Robb Duncan's jaded view of food and drink evangelists and their claims to modern-day miracles (bone broth anyone?). "I was born in the Southeast around religion, so I don’t believe anything anymore until I actually see it," he says. "Sufficient proof."

That proof surfaced during tastings at AC Beverage, where Duncan, Vasquez and Wahid Osman, regional manager for Dolcezza, were convinced that Kleinrichert's system did add something unique to nitro coffee. Depending on the type of coffee (whether a sweet Colombian or an acidic Ethiopian) and the gases used in the system (straight nitrogen or a mix of nitrogen and carbon dioxide), the JoeTap can make a cup of cold brew taste brighter, creamier and/or sweeter. The system will also infuse the coffee with gases, so it develops a foamy, cascading head, much like the one on a pint of Guinness.

"It’s a paradigm shifter in coffee and what coffee can be and what flavors you can get out of coffee," says the formerly skeptical Duncan, who will roll out his JoeTap system on Friday, April 17, when Dolcezza at CityCenterDC opens.

The JoeTap operates differently than standard nitrogen and/or Co2 taps, the kind developed for beer but used for coffee at places such as Slipstream, Meridian Pint, Room 11 and Chaplin's. Nitrogen gas bubbles are too large to infuse quickly into a liquid like coffee, Kleinrichert says. This explains why nitrogen taps mostly push coffee through the lines with little infusion. Some extremely patient, craft-crazy operators, such as Ryan Fleming and Miranda Mirabella at Slipstream on 14th Street NW, will keg their cold concentrate coffee with nitrogen and let it sit for a day or two, occasionally shaking the kegs to infuse the gas.

“They are accomplishing what they need to accomplish," Kleinrichert says. "It’s just not a very efficient method."

Kleinrichert's JoeTap has a (patent-pending) system that breaks down the nitrogen into microscopic bubbles and then mixes the gas into the cold-brew coffee via a special infuser. The system allows customers to use both nitrogen and Co2, or just nitrogen. Dolcezza's coffee team has, through trial and error, decided it prefers a combination of gases, 75 percent nitrogen and 25 percent carbon dioxide.

"Co2 adds like a refreshing pop. I won’t say a 'sparkle.' It’s not sparkling per se," says Dolcezza's Osman who has been experimenting on the JoeTap for weeks. "It makes it effervescent.”
Adds Kleinrichert: "Co2 is a complement. It’s almost like putting salt on food," he says. "That’s because Co2 has a distinct flavor, and you’re putting a small percentage of that into coffee."
But more than that, the JoeTap system can bring out flavors that previously remained buried in a coffee. As those microscopic nitrogen bubbles open up and pop, they "can absolutely bring out some flavors that you wouldn't normally get," Kleinrichert points out, "You're creating unique new flavors that were never found in coffee previously."

Despite the benefits, such a system may not appeal to everyone. Fleming and Mirabella invest a ton of time testing their cold brew coffees and concentrates, endlessly tinkering with the grind, water temperature, room temperature and extraction time until they unlock the right combination of flavors. They don't necessarily want to then put it on a tap system, with Co2 no less, that will instantly alter that balance of flavors. They're looking more for the silky mouthfeel that nitrogen imparts to a cold brew coffee.