North American cafés for some years now have been brewing coffee in advance to refrigerate and serve over ice on warm summer days. The brewed, refrigerated coffee is usually prepared by the cold-brew method: ground coffee is steeped in cool or room temperature water for around ten to twenty-four hours, and after this prolonged extraction, filtered and stored in the refrigerator until it is served over ice. Japanese cafés and traditional kissaten for decades have used special brewing devices to produce cold-brewed coffee, tall, complex, alchemical-looking all-glass towers that often sit in the shop window slowly dripping finished cold-brewed coffee into a matching receptacle. Some American cafés have adopted these Japanese brewers, though the less showy and much less expensive Toddy commercial cold-brew system is widely used, as are improvised systems, which are easy to create given the simplicity of the cold-brew process. An American company, Pure Coffee USA, has introduced a very showy, deco-styled version of the already dramatic Japanese cold-brew towers called The Empire that cold-brews three different coffees simultaneously.
Cold Brew in Bottles
Several years ago some roaster-cafes began offering their cold-brewed coffees in bottles that range in volume from ten ounces to thirty-two or more ounces. These products are distinct from the ready-to-drink coffee-based beverages sold in supermarkets. The supermarket products typically combine sweetener and milk plus preservatives and a sometimes lengthy list of other ingredients. The bottled coffees we tested for this month’s article are the pure, naked thing: coffee and water. They are bottled fresh and they are perishable. Two companies we contacted add a small amount of vitamin C as a preservative; most do not.
The appeal is obvious: brewing coffee hot then chilling it is a fussy process that requires time and foresight, and producing your own cold-brewed coffee at home requires even more time and foresight, whereas pulling a bottle out of the refrigerator and popping the cap on a hot afternoon and pouring the contents over ice is, well, the American way – easy and convenient.
But the question arises: How well do these products transmute fine hot-brewed coffee and its satisfactions into a bottle and from there to ice and a glass?
Tasting Sixteen Bottled Coffees
We tested sixteen bottled coffees intended for drinking over ice produced by fifteen different companies. Fifteen were cold-brewed; one was produced using a proprietary pressure brewing system. Three were concentrates that suggested diluting with water or milk before serving or consuming. In some cases the company that did the brewing, bottling and marketing used someone else’s roasted coffee; in other cases the same company did everything: sourcing, roasting, brewing, bottling, marketing.
We excluded coffees that added milk or sweetener, or contained anything other coffee, water, and in two cases only, a very small amount of vitamin C. We recognize that people do like milk in their iced coffee, however, plus our rating system needs five categories to generate a score, so in place of the aroma category, which struck us as irrelevant for pre-brewed coffee served over ice, we added a “with milk” category. We used whole milk and added a rather small amount to the iced coffee, in a proportion of 1 part milk to 8.5 parts brewed coffee.
Our protocol was simple: We measured 95 grams/milliliters of each bottled, refrigerated coffee, combined it with 45 grams of ice, and did our best to taste it immediately, before the ice had much opportunity to melt. We then conducted a second round of tasting in which we added 10 grams/milliliters of cold whole milk to the same weight/volume of coffee and ice. Again, we tried to move fast after the coffee and milk hit the ice.
We tasted a good deal of variation in these coffees, despite the fact that all but one were cold-brewed. Some of the variation could be accounted for by differences in roast level or color, and some probably by details of the brewing method. But the biggest differentiator seemed to be the green coffee the roasters/brewers started with. The highest-rated Slingshot Coffee Cold-Brew (94) was an Ethiopia coffee, apparently a wet-processed Ethiopia that preserved its bright sweetness and at least some of its fruit and floral character right through brewing into the bottle and from there over the ice. It was not so much that you would be driven to exclaim what a great Ethiopia coffee it was, but simply that the fine, sweet, balanced structure and hints of complex flavors the Ethiopia brought to the bottle provided what for us was a superior cold-coffee beverage experience: refreshing, sweet, gently bright, cleanly fruit-toned.
African coffees appeared to dominate our higher ratings; the 94-point Slingshot was brewed from a fine wet-processed Ethiopia sourced and roasted by Counter Culture Coffee; the 92-rated Alchemy was brewed from a dried-in-the-fruit or “natural” Ethiopia; the 93-rated Black Medicine did not fully disclose coffee origins but it seemed clear to us that there was an Ethiopia, probably a dried-in-the-fruit Ethiopia, in the mix. The 91-rated Pier Coffee Cold Brewed Concentrate was produced from a Burundi, and judging from the crisp black currant, floral and ripe orange tendencies, a good and characteristic Burundi.
Impact of Cold Brewing
Even in the case of very distinctive coffees, the combination of cold-water brewing and cold serving tended to mute flavor notes. The essential structure of the coffee remains – its mouthfeel, acidity, balance of sweet and bitter tastes – but the flavor notes, the fruit, the flowers, the chocolate, were not nearly as clear and distinct as they would be in a coffee brewed hot and served hot. On the other hand, cold brewing encourages sweetness and a light but very smooth mouthfeel, while to some degree reducing acidy bite, a plus for many acidity-sensitive coffee drinkers. We found the best of these coffees refreshing, balanced, and despite the muting of the flavor notes, quietly distinctive.
The Concentrate Conundrum
Concentrate coffees presented a bit of a puzzle for us in regard to evaluation. One clear conclusion we can share: If you follow the manufacturer’s recommendation in respect to the proportion of concentrate to water (or milk) you will probably end with a relatively weak, disappointing cup. We followed the directions on the label for one concentrate (not reviewed here) and found that at the recommended proportions the coffee barely flavored the water. Most concentrate labels were more reasonable, however, recommending equal parts of concentrate and water. We still found these proportions produced a relatively understated cup that failed to show the coffee well; on the other hand, concentrates we tested straight or undiluted seemed a bit too heavy and intense. So we ended up evaluating concentrates at proportions of two parts concentrate to one part water. Slingshot Coffee markets a concentrate as well as its top-rated cold-brew; at two parts concentrate to one part water we rated the cup at 94, a similar rating to the same coffee bottled as a straight-up cold-brew. The Slingshot concentrate is not reviewed here, but the Pier Coffee Concentrate does appear here at 91, and proved a quite attractive and balanced cup at our two parts concentrate to one part water formula.
The best of these bottled cold coffees seemed to us to deliver a product worthy of the North American specialty industry: less distinctive and less pronounced in character than analogous hot-brewed coffees, but smoother, more refreshing, yet still distinctive enough to surprise and engage.