The seasonal nature of the coffee plant is important, but, day-to-day, the seasonal nature of coffee drinks is what matters for most people. In the summertime months, we typically find ourselves ordering iced versions of our cold-weather drinks: iced lattes, iced mochas, iced coffee, and so on. But the real star of the cold coffee season is cold-brewed coffee, which has been a stalwart of specialty coffee companies, especially Stumptown and Blue Bottle, for years, and is now taking center stage of the mainstream with Starbucks. But what exactly is cold brew, why is it better than iced coffee, and how can you make it at home?
We turned to Stumptown Coffee's Diane Aylsworth, in part because Stumptown are such fans of cold brew that they own the URL coldbrew.com, and also because their retail cold brew has, for years, been quietly pleasing caffeine-hungry consumers smart enough to buy it. The key to cold brew, according to Aylsworth, is in the low temperature, slow process brewing, and knowing which coffee to pick.
"Cold brewing is a long steeping process where the cold or room temperature water steeps with the coffee grounds for over 12 hours. It is a gentle process to extract the flavors from the coffee. It results in a smooth, low acid cold coffee," she said. "Traditional iced coffee is brewed hot and then cooled down over ice. This typically leads to a harsher, bitterer tasting cold coffee."
Not only does cold-brewed coffee have an overall smooth, "chocolate-y" taste, it’s got more caffeine, too, said Aylsworth. "The concentrate," which is what results from the cold brewing, "is definitely higher — after we cut it with water in a 1-to-1 ratio, the result is approximately 30 percent more caffeine than a hot brewed cup of coffee, on an ounce for ounce comparison."
And, even though the brewing process is made to round out the harsh flavors of most types of coffees, the brewers at Stumptown have a preference — and so should you. "We use Latin American beans, which lead to a sweet and smooth cold brew with a nice chocolate finish." Our advice? If you can’t find a Latin American single origin coffee on the shelves of your local shop, turn to their espresso or house blends, which are typically formulated to be as generally pleasant as possible, which is a perfect match for the people-pleasing cold brewing. Stay clear of particularly floral origins, such as Ethiopia. It'll taste fine, sure, but it won't be as good as it can be. Which is what we're looking for.
- The above guides differ on how to grind your coffee, but a coarse grind has always worked for us. Do it for yourself on a home grinder, or just ask your barista to grind them the same the café grind theirs for cold brew.
- Buy one of several types of cold brew systems. (We recommend against cold brew French presses, seeing as the minimal filtration in French presses allows for excess oil in the brew, and so results in a less smooth concentrate and effectively defeats the purpose of cold brewing.)
- Follow the basic instructions of whichever system you bought, and let the coffee steep for between 12 and 24 hours. Aylsworth and Stumptown suggest 16, but an extra hour or two won’t hurt. Cold brew is, in a way, foolproof.
- Once the steeping process is over, store the resultant concentrate in an airtight container. It should last you at least a week. We think it tastes best when diluted just before drinking, and if you’re a fan of lattes, skip the water in the dilution process and make yourself a 1-to-1 cold brew/milk drink. Just be careful: This concentrate is super caffeinated.
That's it. Cold brewing is pretty simple, even though the neologism can seem scary, and the barrier to entry seems high. Like the flat white and all of the drinks-of-the-week that came before it, cold-brewed coffee goes in and out of favor every once in a while, but regardless of whether or not its chocolate flavor is in fashion, it's always pretty damn easy to make it right in your own home.