The main thing you need to know about cold brew is right there in its name: It’s coffee that’s brewed using cold (or, really, room temperature) water, rather than hot water. The process takes longer—most methods call for an overnight steep—and the result is a coffee concentrate that tends to taste less acidic than other iced coffee methods. The concentrate can be kept in the fridge for up to two weeks, and diluted with cold milk, alternative milks like oat milk, or water on ice to drink. That’s arguably one the best things about cold brew: You can make a lot at once, then enjoy it with almost no effort after that.
Whether cold brew’s lower acid flavor profile is a good thing, though, is a matter of debate. In our own blind taste tests, most tasters didn’t prefer cold brew when served black. Mixed with creamy dairy, though, and cold brew’s qualities shined. That doesn’t mean you shouldn’t drink your cold brew black, but we’d encourage you to experiment with different brewing styles based on how you prefer to take your iced coffee.
Despite all the products out there trying to convince you otherwise, there’s really no special gear you need to make cold brew. As long as you have a large enough vessel to hold the coffee grounds and water, and something to strain it through (you know, like a…coffee filter), you’re all set.
Note that this recipe makes a 1:6 ratio concentrate by weight (so, for every 1 gram of coffee, you’ll be using 6 grams of water). When serving, you can and should dilute the concentrate to taste, but a 1:2 dilution by volume is a good starting point (so, for every 1/2 cup of coffee concentrate, add 1 cup of milk, water, or other liquid).