RTD Coffee Report – 10 Ready-to-Drink Coffees by Coffee Review

While so much in the world of coffee gets “curiouser and curiouser” each year, to echo the protagonist of Lewis Carroll’s Alice in Wonderland — from increasingly complex, mysteriously named green coffee processing methods to new hybrid varieties of Arabica born of necessity to respond to climate change — specialty coffee is a living entity, its success defined by an ability to adapt, both to consumer desires and geo-political realities. So, it’s refreshing, literally and metaphorically, to find that the ready-to-drink (RTD) market of cold black coffee, unadulterated by sugar or other additives, is — well, simple — or at least aspires to simplicity. Because simplicity is clearly not the coffee norm, these days. And yet, it suits the primary aim of each and every roaster we spoke with who submitted an RTD coffee for our July report: to achieve the clarity and balance of the best hot-brewed coffees.

There you have it, a consensus among disparate factions of the coffee community, from roasters both in the U.S. and in Taiwan who submitted samples for this report. And the aspiration for RTD coffees to resemble the experience of hot-brewed is not something that’s been discussed much in coffee forums. Cold brew has always been presented more as a lesser substitute for properly brewed hot coffee, either because the weather coaxed its appeal or because the apparatus for brewing was not readily available (temperature-controlled kettle, burr grinder, etc.). Most cans of RTD coffee on supermarket shelves are not terribly distinctive, frankly, are more caffeine delivery vehicles than sensory discoveries.

We at Coffee Review have been exploring RTDs for as long as they’ve been trending, and there’s always been a fair degree of randomness to what we’ve rated highly — not in terms of each discrete coffee but in terms of a takeaway for the genre as a whole. In past years that we’ve reported on RTDs, we turned up excellent cold coffees, but we identified no clear themes or throughlines regarding what performed well. This year, for whatever reason(s), RTDs appear easier to grasp, conceptually, not to mention delicious in their execution — in fact, simple, elemental, like the best hot-brewed coffees.

2021 has brought into focus what is basic and fundamental, and the 10 RTD cold-brewed coffees we review here, rated 92-94, have the common denominator of being simple, in the best sense of that word, in their brewing method or cup profile, or both.

Of the 10 reviewed coffees, only the Highwire was “flash-brewed,” i.e., brewed hot before being immediately chilled. The other nine were either brewed using the immersion method (see below for roasters’ detailed descriptions of variations on this theme) or the traditional Kyoto method, in which ice-cold water drips very slowly through a bed of ground coffee.

Cold Brew Is Slow Coffee

Another hallmark of post-pandemic life seems to be a re-embrace of slowness as a value. We were forced to slow down and hunker in for more than a year, and many of us liked it so much that we want to retain elements of the pace that allowed us space — not only between meetings and deadlines, but perhaps our very thoughts themselves. Cold-brewed coffee is, by nature, a slow brewing process, a waiting game, in fact. The basic process is to immerse coffee grounds in cold water for 18-24 hours, which allows flavors, oils, and caffeine to be extracted from the coffee — then filter, and voilà — you have something that approaches drinkable. Maybe. But there are challenges for the home brewer of cold coffee.

It often can turn out muddy with sediment, over-extracted to the point of bitterness, and a hodgepodge of the sensory characteristics of the original green coffee that might be quite pleasing in a correctly crafted hot brew.

More than 25 companies manufacture and sell cold-brew equipment for home use. But maximizing the sensory potential of these subtle brewing methods at home can be tricky. And there may be health issues to consider, as well, given that coffee is a low-acid beverage that invites contamination if it is not properly handled and refrigerated. Getting your RTD coffee at a café or roastery that has dialed in the process is still your best bet.

The roasters who submitted the RTDs we rated highest for this month’s report all expressed as their chief goal to make an RTD coffee that, experientially, gives people the same experience as drinking an excellent hot-brewed coffee: clarity, depth, nuance, aesthetic satisfaction. And each also found this path by the least circuitous route possible — either a simple immersion method or the equally simple, but painstaking traditional slow-drip or Kyoto method (in the case of two of the brewers). Some were completely transparent about each step of their production method, while others were more reticent. After all, simple isn’t necessarily easy.

The Single-Origins

Of the 10 RTD black coffees we review this month, three are single origins and seven are blends. Of the blends, five are also served by the roasters in hot-brewed format, while two are designed expressly for cold brewing.

Taiwan-based GK Coffee’s Brazil Ipanema “Lychee” RTD cold coffee. Courtesy of Gary Liao.

Perhaps not surprisingly, the two top-rated (at 94) are single-origins, both offering the pleasures of precisely sourced, carefully processed and roasted green selections — in this case, both natural-processed, a Brazil and an Ethiopia. Taiwan-based GK Coffee’s Brazil Ipanema Golden Edition C26 Lychee is a tropical, tart-leaning, richly fruity cold coffee (packaged in a cool hipster-esque flask) that roaster Gary Liao says is very popular in a country as warm as Taiwan. He brews it over 4-6 hours at a 1:15 coffee-to-water ratio (as he would a pourover) using special cold-brew equipment in a refrigerator set to 1 degree Celsius, then filters before bottling.

Roast House, based in Spokane, Washington, sent in the Ethiopia Mormora Cold Brew, a decadently tart, chocolaty and richly savory RTD brewed using a custom cold brew system in a ready-to-drink recipe not further disclosed by head roaster and green buyer Aaron Jordan, who says the goal was “to produce as close to a hot cup experience as possible.” He adds, “We target sweetness, mouthfeel, flavor clarity and shoot for a clean finish. Sourcing a grade 1, organic, natural processed coffee fit all that we were looking to bring to a 12-ounce bottle of RTD cold brew. Our passion at Roast House has always been to source 100% organic and sustainably produced coffees, and to be able to put those values in a bottle that someone can crack open anywhere they find themselves allows us to continue operating within our values. RTD brings specialty products to consumers in an accessible way, and, for that reason, we see the RTD market becoming more and more attractive to industry professionals and consumers, alike.”

Roast House’s limited-release Ethiopia Mormora cold-brewed coffee. Courtesy of Roast House.

Grove City Pennsylvania’s Collage Coffee sent us a Kenya Cold Brew that landed at 93 for its multi-layered, richly sweet-savory cup that clearly represents its origin. Owner Joe Funte says he likes to use a Yama tower for cold brew with a medium-ground coffee. This method involves the slow drip (rather than immersion) of ice water over a bed of coffee grounds. (The brewing tower is also visually dramatic and fun to watch in action.) Funte says he was looking for something clean, bright and fruity for summer, and this Kenya fits the bill. Of the trend in general, he says, “I think the RTD is here to stay, though I think it will continue to evolve. Unlike hot-brew specialty coffee methods, it allows roasters to give customers the finished product for them to enjoy anywhere without having to rely on their knowledge, skill, or equipment to brew a coffee to its full potential. You don’t hear of a craft beer brewery or distillery selling its mash to customers to finish brewing/distilling at home — RTD coffee lets us use our professional equipment and our perfect brewing water to bring the same quality to customers in a much more accessible package.”

Collage Coffee’s Kenya RTD, brewed in a slow-drip Yama tower. Courtesy of Collage Coffee.

The Blends

The seven RTD blends we review here gave us a range of sensory pleasures, from richly chocolate-driven to fruit-forward and spice-toned.

Auto Coffee, based in New Taipei City, Taiwan, submitted a cold brew that’s a blend of two Ethiopia coffees, one natural-processed and one washed, resulting in a deep, complex, beautifully structured cup (93), floral and citrusy. Owner Daniel Yao says that many of his customers order cold brew more for the caffeine hit than the flavor, and they’re surprised when they find it tastes good.

Auto Coffee, based in Taiwan, offers a single-origin RTD Ethiopia blend. Courtesy of Auto Coffee.

Also rated at 93 is Chicago-based Big Shoulders’ aptly named Black Cold Brew, a blend of Ethiopia, Uganda and Colombia coffees that yields a caramelly and spicy floral cup animated by notes of date and bergamot. Owner Tim Coonan admits that he prefers hot coffee, “even as a heat wave is raging across the U.S.” But he says, “Cold brew is most assuredly not a passing trend. We have long been complimented for the cold brew we serve in our cafés, and we wanted to reach a broader audience with a canned RTD product. We are striving for a light and crisp approach with some balancing acidity and fruit. We roast specifically for cold brew using three different origins and roast styles to help us reach that goal. We use an 18-hour cold-temperature extraction and finer-than-normal grind to get these results.”

Chicago-based Big Shoulders’ 12-ounce cans of black cold coffee. Courtesy of Big Shoulders.

San Jose, California-based Chromatic Coffee collaborated with the cold-brew producer Dripdash to can its popular blend of Brazil, Ethiopia and Guatemala (called “Gamut”) in RTD form (93). This is our other example of Japanese-style cold-brewing, in which ice-chilled water drips through a bed of ground coffee over the course of several hours per batch. It’s a savory-sweet coffee that reminds us of sassafras and toffee.

A pair of home slow-drip cold coffee makers. Larger versions were used to produce two of this month’s reviewed coffees.

Corvus Coffee in Denver, Colorado, a frequent player in the RTD scene, starts with its tried-and-true flagship espresso blend, Dead Reckoning, this season from Ethiopia and Brazil, the cold-brewed version of which (93) owner Phil Goodlaxon says “is intended to have a flavor profile reminiscent of chocolate-covered berries — fruit and sugar-browning in equal strength held together in a good structure. We have a washed Ethiopian (Bole Hora from Guji, a direct trade partner for us) and a natural Ethiopian (Yukro Jimma) combined with a natural process Brazil from Caparao, where we’ve been getting some nice larger lots that have a lot more fruit than ‘typical’ large lots of Brazil; it’s a farm called Santo Agostinho.”

Highwire Coffee Roasters, a local favorite here in the Bay Area where Coffee Review is based, has an approach to RTD that’s different from the immersion method without breaking the “simple” paradigm. Its flash-brewed coffee, a blend of Guatemala, Costa Rica, and Papua New Guinea we rated at 93, is made by hot extraction followed by rapid cool-down. Co-founder Rich Avella says, “We’ve always loved the flavors only possible with hot extraction, cooled quickly to lock in the aromatics.” He continues to say, “We use a coffee for Flash that we blend and roast to highlight crisp, high-end and clean flavor, with round texture. Coffees from Antigua [Guatemala], Tarrazu [Costa Rica], and Papua New Guinea combine to deliver a crisp, refreshing, and substantial cup with a lingering sweet finish.”

States Coffee, also up and coming in the Bay Area with a new bakery and coffee shop opening in Berkeley this Fall, calls its dark-brown beer-like bottles simply Cold Brew (93). Owner Keith Gehrke uses five-gallon stainless steel brewers and Toddy filters: “We grind what we would use for drip and steep overnight (not 24 hours). We also use warm water, not cold.” States’ cold brew is a deeply chocolaty, almost fudge-like, cold brew pleasingly complicated by hints of raspberry and molasses.

Roaster Heather Brisson-Lutz in her Maui-based RTD brewhouse at Origin Coffee Roasters. Courtesy of Origin Coffee Roasters.

Maui-based Origin Coffee Roasters is the most high-tech operation among the companies discussed here, by a long shot. Owner Heather Brisson-Lutz, whose simply named Cold Brew Coffee we rated at 92, says, “We have a unique set up for all our cold-brew processing/manufacturing since we are located inside Maui Brewing Co. The brewery co-packages our RTD nitro brews on its multi-million dollar canning line, giving us a step up in quality. We utilize their lab for in-house testing throughout the entire process, recording important data from brewhouse, brite tank, flash-pasteurization and, finally, the canning process. She adds that, during the canning process, “each can is dosed with liquid nitrogen and seamed immediately to reduce oxidation in the final packaged product. Samples are then sent to a third-party lab to ensure that our cold brew meets our standards and all food safety regulations before being introduced into the market. Since our cans do not have a nitrogen widget [a small plastic reservoir containing nitrogen] inside the can, they do require a little work before opening. We suggest a light shake before opening, then inverting the can and giving it the ‘hard Guinness pour’ to allow the liquid nitrogen to integrate into the cold brew. This produces the nice cascade desired in nitro products.” The end result is a refreshingly tart, crisply sweet cold brew, balanced, bright, and delicately chocolaty.

To Nitro or Not to Nitro, That Is the Question

The addition of nitrogen gas to cold-brewed coffee gives it a fizzy lift and, often, a plush mouthfeel. (It’s possible to produce your own cold nitro brew at home with one of several mini-keg devices selling for around $140 to $200.) We’ve segregated the topic of nitrogen infusion as a separate issue because, ultimately, this is purely a matter of preference, kind of like whether you prefer still or sparkling water. That said, nitrogen contributes to beverages a particularly delicate, fine-bubbled, often velvety texture, different from the often coarser, big-bubbled impact of CO2.

A cold nitro-brewed coffee on a hot summer day.

We’ve tasted enough RTDs to say with some confidence that nitro versions of coffees differ from still versions mainly in the mouthfeel — the fizz doesn’t much influence the flavor profile, but it changes the mouthfeel profoundly and sometimes gives the acidity a perceived cola-like (or phosphoric) edge.

The RTDs here that are offered as nitros are the Corvus Dead Reckoning and the Origin Cold Brew (whose precise process is detailed above). We found that the addition of nitrogen adds another layer of refreshment to already bright, juicy blends.

RTD Is Here to Stay

RTD coffees are not a passing fancy, and with ongoing refinements to this very simple brewing technique — variations on a theme, if you will — look to find a wealth of options from local brewers hitting the market this summer.

Hiver van Geenhoven of Chromatic Coffee sums it up best: “Since craft beer exploded, canning technologies and access to them have improved, and cans are back in style. Better-tasting options permeate the RTD market and grocery store cold-aisles. People love sharing their favorite brands wherever they go, and RTDs remove some of the barriers that make it intimidating even for coffee lovers to check out new brands — like the challenge of correctly brewing a cup or fear of encountering judgment at a new shop.”

This is good news for lovers of high-quality coffee in any form. Let us know what you find out there by tagging us on Instagram @coffeereview. Cheers!