It’s summer, or at least pretending to be summer, and thus the season for iced coffee. Almost every coffee shop will have a version: some clouded with dairy products and laden in sugar, invariably more expensive than a plain cup of joe, and slurped down far quicker. Leaving aside frozen concoctions and desserts disguised as drinks — affogatos; Vietnamese coffee; Viennese coffee; and caramel-laced, whipped cream-based treats — there are generally two ways in which iced coffee is prepared in specialty coffee shops: cold brew steeped for hours or hot brewed over ice (known as ice brew).
There is a significant difference between these methods, and they make for vast variation in the resulting aromatics, level of quinic acid, and, of course, taste. Many would-be coffee drinkers cite coffee’s acidity as a stomach irritant and favor cold brew which lowers the pH level. For the few who are that sensitive, it’s fortuitous, but is it really a primary selling point?
Hot coffee is indisputably acidic, and since the pH scale is logarithmic, the increase from a pH near 5.5 to 6.3 (see chart below) is significant. However, if coffee is considered especially acidic, then carbonated drinks, alcoholic drinks, juices, sports drinks, and many bottled waters, should be considered more so and avoided as avidly.
In the coffee world, and to some extent, the media, a debate has slowly brewed over which is the best method. For consumers, this mostly matters if you are brewing your own at home, but even if you don’t, you may want to know which version you prefer for the next time you’re looking for cold brew around town.
Comparing Brew Methods
Ice Brew (AKA: Japanese iced coffee, “flash brewed”)
Hot-brewed coffee (not espresso) is rapidly cooled over ice and immediately drinkable because the ice is factored into the water-to-grind ratio. The operative word is “rapidly.” The stuff you find in bodegas, street carts, and faux coffee joints, is not ice brew coffee; rather, it’s hot-brewed coffee allowed to cool and oxidize, then served to customers in a cup of ice, still overpriced and underwhelming.
Those who champion ice brew coffee refer to the resulting style and complexity with wine-like terms such as aromatics, varietal character, and terroir. They claim that cold brew tends to be flat and loses nuance of flavor. Consequently, ice brew should ideally be drunk black, unadorned with milk or sugar.
Benefits: retains the character of the roasted beans; preparation time is not much longer than that for a pour over cup, and brew time is shorter by hours to days compared to cold-brewing; immediately drinkable without the need to dilute or adjust afterwards.
Cons: you still need sixth grade math knowledge on ratios. Since the ice will dilute the coffee, this must be factored into the ratio of water to grounds.
Proponents: Peter Guiliano (former director of coffee at Counter Culture), Sam Penix (Everyman Espresso), and Oliver Strand (New York Times).
Where to Taste: Hi-Collar, Everyman Espresso, and Gasoline Alley.
Coffee grounds, often in a proportion that is designed to create a concentrate rather than an immediately quaffed drink, are steeped for hours, often overnight, at room temperature. Cold brew can now be delivered nitrogen-charged and on tap at Stumptown, bottled like a beer growler at Birch Coffee, or served in kegs at the office. It should remind you of beer and shares some of the characteristics of porter or stout. Those who favor this style extol the smooth, chocolaty, sweet experience that coats the mouth. Only in vogue less than a decade in NYC, cold brew can now be found in most specialty coffee shops.
To make things confusing, there are two primary ways to make a cold brew. The far less common, but more theatrical, method can be described as Japanese — not to be confused with the Japanese iced coffee practice of brewing over ice. The slow-drip coffee brewers, also known as a Kyoto dripper, are tall and as garish as a bowling trophy, but far more rare. These contraptions can be found in Blue Bottle’s Williamsburg shop or Birch Coffee’s West Village shop on Seventh Avenue. This method is said to preserve the flavor and subtleties of the bean’s origins, akin to the ice brew. After five hours — or sometimes 12 — the drink is ready.
The standard way to make cold brew requires an even longer steeping time than the previously mentioned drip towers. The original and most prominent brewing device is the Toddy. This blunt, plasticky apparatus is decidedly un-Japanese, but very simple in concept and design (the original was created in the Mad Men era); it’s essentially two containers separated by a filter and a stopper.
Benefits: smooth, lower acid; great with milk; can be prepared in large quantities and served quickly in a café; requires minimal skill; can be used for commercial retail in containers; does not require training for a coffee employee to serve.
Cons: removes the bright, nuanced flavors of single-origin coffee; the home user must wait hours, or overnight, after preparing; will often be diluted when served to a customer over ice.
Proponents: Scott Rao (noted coffee book author, instructor), Lorenzo Perkins (Barista Guild of America Executive Council), most food & home media, virtually all specialty coffee shops who need to move product quickly.
Where to Taste: this method is far more common and can be found at Stumptown on West 8th, Third Rail, Café Grumpy, Ninth Street Espresso, Think, Joe, La Colombe, Gimme! Coffee, Kaffe 1668, etc.
Buy it in bottles: New York’s own Birch Coffee, Gorilla, Grady’s, Kickstand, or pop into Nolita Mart, Whole Foods, Gourmet Garage, Dean & Deluca, and Union Market, or order online through FreshDirect.
The bottom line? You now have more and better choices than ever to stay cool and caffeinated all summer.