Why Iced Coffee Is So Damn Good
Cold brew over everything.
BY Sarah Rense | May 17, 2017 | Food & Drink
There are two camps when it comes to iced coffee. The first claims iced coffee is good, while the second holds that iced coffee is extremely good. As the sun makes its first wavering springtime appearance and the temperature reaches around 70 degrees, hot coffee suddenly seems obsolete.
And in all actuality, iced coffee is better than hot coffee, for reasons we will get to in a moment. Especially now that cold brew, the superior cousin to hot brew, is appropriately mainstream. A lot of smaller coffee shops use the cold brew method for iced coffee. A cold brew coffee is made by running cool water through coffee grounds, a process that takes far longer than brewing a hot pot of coffee and pouring it over ice. It's worth the wait, though. "We prefer to cold brew just for the complex profile that you're left with at the end of the process as opposed to hot extraction over ice," says Stumptown Coffee Roasters associate brand manager Max Bauske. "Just a bold, sweet, and balanced brew that you can't get through that hot extraction method."
Here's a quick summertime guide to iced coffee—hot brew over ice or cold brew.
Coffee has terroir:
Iced coffee tastes different (better) because it is different (better). Coffee beans, like any crop, are harvested depending on the climate in which they are grown, so beans picked for the summer months have different properties than wintertime beans. Variety Coffee, a small chain in Brooklyn that uses single-origin coffee, sources summer products (like beans for cold brew) from farmers in the Guji region of Ethiopia. "Those coffees tend to be the fruitiest coffees, the most dynamic coffees, and the most exciting coffees," says owner Gavin Compton. In other words, he says, "The coffees that are available in the summertime are all the best coffees that are available all season."
Alternatively, Stumptown sources its cold brew beans primarily from Colombia, Guatemala, Costa Rica, and Nicaragua, according to Bauske. And Blue Bottle Coffee's cafes offer iced black cold brew made from its Three Africas blend, says Michael Phillips, director of training. Those blends tend to be consistent from season to season, while single origin offerings fluctuate with the seasons, tasting uniquely of the soil, tree, farm, and climate in which they are grown—the "terroir" of the coffee, as Compton says.
So, to each coffee shop and brand its own—but there's a good chance summer beans suit certain palates better.
It's all about pulling flavour from the beans:
On a molecular level, brewing a hot pot of coffee is a much more violent process than the gentle coddling of cold brew. The heat required for hot brew bounces the molecules at high speeds, quickly yanking chemicals—"flavonoids and chlorogenic acids and all the things that make coffee good," says Variety director of coffee Erika Vonie—from the beans. That's why a pot of coffee takes no more than 10 minutes to brew. The cooler water used for cold brew is molecularly calm by comparison, taking upwards of 20 hours to coax deeper flavours from the beans. "Characteristics of cold brew are that it has thicker body, it has much more even flavour notes—usually of dark chocolate or chocolate in general—and dark berry notes," says Vonie.
The brewing process makes hot brew more acidic, a trait that carries over to hot brew poured over ice, whereas cold brew is "low acidity, more truffley, more basey, but still crisp and clean," says Phillips. Easier on the stomach that way, too.
It's perfect for the black-coffee-averse:
Cream, sugar, Stevia in the Raw, almond milk, and all other add-ins are a highly personal matter, especially when iced coffee tastes differently from shop to shop. But if you don't want black coffee, Phillips recommends cold brew iced coffee. "It tends to be a more heavy-handed flavour profile, and it'll cut through that milk with a little more strength and intensity, whereas the hot brew over ice tends to be more delicate the way people brew it," he says. Add-ins can drown out the good coffee flavour in a hot brew, whereas milk and sugar better complement the cold brew.
If the end goal is purely caffeine-oriented, then choose undiluted cold brew. "In terms of strength, that's probably about twice as strong as your average cup of hot coffee," says Phillips. "It'll be some rocket fuel for you." Even diluted with water, it's the better bet. Vonie explains that caffeine is one of the last chemicals to be extracted from coffee, and because cold brew sits for longer, "every single ounce of caffeine that can be pulled out of the coffee will be pulled out of the coffee."
Hot brewed iced coffee, alternatively, is for suckers—by its nature, it has to use less coffee to make room for ice in the cup, unless you take a more scientific approach to making it. Here's Phillips' very scientific approach: Subtract the weight of the ice you want to use from the amount of water you would normally use to brew a hot mug. "When it hits the ice, it dilutes to achieve that proper strength," Phillips says, retaining the same amount of coffee (and caffeine) per serving.
For reference, here's the caffeine breakdown for Starbucks, Dunkin' Donuts, and Seattle's Best, based on info from Caffeine Informer. For health and sanity's sake, research indicates that up to 400 mg of caffeine a day is a safe amount for most adults.
Hot coffee (medium roast): 310 mg
Hot brewed iced coffee: 165 mg
Cold brew coffee: 200 mg
Dunkin' Donuts Medium:
Hot coffee: 210 mg
Hot brewed iced coffee: 91 mg
Cold brew coffee: 260 mg
Seattle's Best Medium:
Hot coffee: 330 mg
Hot brewed iced coffee: 45 mg
Cold brew coffee: N/A
Making iced coffee at home:
Homemade iced coffee is easy enough—just brew a pot of coffee and add ice. There are also plenty of filters on the market to make cold brew, and plenty of summertime beans and cans sold by retailers. Cold brew can be stored for long periods of time—like brewing a batch on Sunday to last the whole week—though Compton recommends freshness so the coffee doesn't over-oxidize. "You never want to drink an old cup of hot coffee; why would you want to drink an old cup of cold brew? Same idea," he says. Or just buy it pre-made. It's quality you're after, not the bargain.