Cold brew has a devoted following for good reason. Because the grounds steep in cool water instead of hot, the coffee comes out smoother and less bitter, letting the subtler notes of the beans come forward. Coffee shop versions can get pricey, though, and the good news is that one of the most common pieces of kitchen equipment already does the job beautifully: the trusty French press.
Testers at America's Test Kitchen experimented with all kinds of unusual tricks, from nearly constant stirring to steeping in the fridge for days. In the end, the simplest approach won out. Start with whole beans and grind them yourself right before brewing, since pre-ground coffee loses its aroma quickly. A medium roast is a sweet spot, tasting more like coffee and less like the roasting process.
The simple method
Combine the grounds and water in the press. After about ten minutes, a thick raft of coffee will float to the top, so give it a stir to make sure every bit gets soaked. Then leave it alone at room temperature for a full day. The testers tried everything from half a day to three days and found that roughly 24 hours delivered the best flavor every time.
To finish, pour the concentrate through a fine-mesh strainer lined with a paper coffee filter, then gently press the leftover sludge with a spatula to coax out the last drops without letting grit slip through. Dilute the concentrate with water or milk to taste, pour it over ice, and enjoy a café-worthy glass that you made while you slept.
Source: America's Test Kitchen
