A Guide to Summer Coffee

Practically an official season on the calendar, the time of year when we stop drinking coffee from steaming mugs and start pouring it over ice is a time worth celebrating. But a refreshing cold brew, iced coffee drink, or even a creamy nitro coffee doesn’t need to necessitate a trip to the coffee shop—if you can brew it hot, you can brew it cold. We tapped industry pros, from coffee roasters and Q graders to coffee shop owners and baristas, to share their advice for making the best possible cold coffee at home.

Cold Brewed vs. Snap Chilled

“Cold brew” and “iced coffee” are not synonymous. Rather, the terms point to the two basic methods by which cold coffee can be created, with each yielding different results in the cup. “The two forms of extraction achieve different objectives. Cold water extracts different flavor compounds than hot water,” says Júlia Peixoto Peters, owner of Peixoto Coffee in Chandler, Arizona. “The way the chemical reactions happen during extraction means the end result of using cold versus hot water will translate into a completely different beverage.”

Cold brew is exactly what it sounds like: Coffee is brewed with cold water via extended contact, either through full immersion or a slow-drip brewer. Iced coffee (also called flash-brewed or snap-chilled) starts as hot brewed coffee before being rapidly chilled. 

Specialty brewers and gear exist for both methods (see Brew Gear below for some options), but they can also be made with whatever you have on hand, such as a large jar for steeping cold brew, or a pour-over cone for brewing over ice. The method you choose will depend on your tools, the time you want to spend, and the flavors you ultimately want in your cup. 

“Because flash brew uses hot water, it’ll result in a cup with more of the flavors you’d find in the hot version of that coffee. It’ll preserve more aromatics and refreshing tartness than cold brew, because cold water is bad at extracting acidity,” explains Maciej Kasperowicz, director of coffee at subscription service Trade Coffee. “Cold water is pretty good, however, at extracting the flavors caused by sugar-browning reactions in the roast, so if you like coffee that’s chocolatey, nutty, and/or roasty and don’t care about that fruity acidity, cold brew might be the method for you.”

What Is Nitro?

Depending on who you ask, the first whisper of liquid nitrogen in connection to food dates to a Victorian cookbook from 1890. In the century-plus since, it’s slowly come for a variety of food groups that skew creamy—ice cream, beer, and, more recently, cold coffee.

Nitrogen is an odorless, unreactive, and inert gas that creates finer bubbles and a creamier texture in liquids than carbon dioxide. Think of the taste and feel of a Guinness when compared to a typical beer; that’s nitro. When infused into cold coffee, either snap chilled or cold brewed, the gas cascades through the coffee and gives it a sweeter, milkier flavor without sugar or milk, and a foamy head.

“It really adds incredible texture and creaminess to it,” says Proud Mary’s Nolan Hirte. “Especially with a nitro infuser right before the tap, so it’s just adding nitrogen right at the last second—it tastes so freaking good. It can be a negative if it’s not done properly. You can almost taste the gas if it’s been sitting around for a while, [though] in theory you shouldn’t taste anything and it’s really clean for that reason.”

Even the cold, creamy taste of nitro coffee can be prepped at home with the right tools. (See the Brew Gear below for details on an all-in-one unit that delivers nitro on-demand.) “When it’s brewed correctly, very expressive coffee cooled down very quickly, and then you add nitro at the last second, it’s hard to beat that,” says Hirte.

The Golden Ratio

Just as with hot-brewed coffee, the proper ratio of water to coffee is crucial for a balanced cup—and few things are as disappointing as weak, watery coffee. The aim with cold coffee is to create a concentrate that can be diluted (with either water or milk) to preferred strength. For cold brew, the industry standard is a ratio of 1:8 coffee to water. For every gram of ground coffee, you would add 8 grams of water (and measuring by weight will always yield the most accurate results).

“For cold brew, my big tip is to pay attention to your brew ratios,” says Kasperowicz, who follows the 1:8 guideline. “When you pour it over ice, you basically get the same amount of caffeine as a regular coffee with no risk of it being watery. The way some folks chug cold brew, if you don’t pay attention to how strong you’re brewing, you can really get zooted pretty quick.”

When brewing flash-chilled coffee, the same general principles apply—brew a concentrated coffee by replacing half of the hot water with ice below. “We use a pour-over or drip machine in much the same way we would for hot coffee,” Kasperowicz says. “But we use around half the amount of hot water and let it drip directly over ice, immediately chilling it and, as the ice melts, bringing it back to proper strength.”

When in doubt, aim strong. You can always add more water to dilute. Júlia Peixoto Peters begins with a ratio of 1:6 coffee to water for her cold brew, allowing the ground coffee to steep for 18 to 20 hours. For serving, her starting point is 2 parts concentrate to 1 part water, with any further dilution (whether milk or water) added to taste.

“Coffee is really all about your preference, so there’s not a right or wrong answer,” adds Jiyoon Han of Bean & Bean. “Give your recipe a try, and if you like it, then keep doing what you’re doing and, if not, you recalibrate and switch things up in the recipe.”

A Note on Extraction

“Coffee extraction is always a function of time and temperature: the two Ts,” says Han of Bean & Bean. Keep them in mind when putting together your cold coffee, from grind size to desired final product. There are certain compounds in coffee that will only be expressed via hot extraction, says Han. These are represented in pronounced characteristics of acidity and floral notes in flash-chilled coffees. On the other hand, cold brew takes a low and slow approach. “Given that cold-brewed coffee is a longer extraction,” says Peixoto Peters, “the cold water will extract some of the initial acidic compounds in coffee but will be balanced by the sweetness and body, which are more easily perceived in the extended extraction that happens in cold-brewed coffee.”

Brew Gear

Whether you’re steeping cold brew, flash-chilling hot coffee, or even making your own nitro coffee, there’s an abundance of gear options. Here are three we like to use.

OXO Compact Cold Brew Coffee Maker

This petite (and easily storable) system makes cold brew via full immersion. Simply add ground coffee to the upper container, snap on the “Rainmaker” attachment for even saturation, and slowly fill with water. Let it steep for 12 to 24 hours, then place the brewer on top of the glass carafe. The bottom valve will open and filter the coffee into the carafe, yielding 24 ounces of cold brew concentrate. $34.95

The Coldwave

To make snap-chilled coffee without any ice, The Coldwave is a quick and easy option. The pitcher insert, with its grid of frozen tubes, is kept in the freezer until ready to use. Simply brew hot coffee to your desired strength, add it to the pitcher (which holds 16 ounces), then snap in the frozen insert. The coffee will be completely chilled in 90 seconds with zero dilution. $39.95

uKeg Nitro Cold Brew Coffee Maker

While the uKeg growler is more of an investment, the ability to make velvety nitro coffee on-demand is decidedly worth it for devotees of a creamy glass of cold brew. With a 50-ounce capacity, the uKeg Nitro Cold Brew Coffee Maker functions as an all-in-one unit for both steeping the coffee and keeping it fresh on tap, delivered via a pressurized nitro system charged with replaceable nitro cartridges. $219