Step 1

Make the cold-brew concentrate: In a 3-quart (3-liter) pitcher, combine the water and coffee, and gently stir to ensure all of the grounds are moistened. Cover the pitcher, and let sit at room temperature for at least 14 hours and up to 24 hours.

Step 2

Set a large fine-mesh strainer over a large bowl and slowly pour the coffee mixture through. Let sit for 5 to 10 minutes to extract as much coffee concentrate as possible, then discard the coffee grounds.

Step 3

Rinse the strainer and pitcher thoroughly. Set the strainer over the pitcher and line it with 4 layers of cheesecloth. (If your strainer is too large for the pitcher, use a smaller one or do this step over a clean bowl, then decant the strained concentrate into the pitcher.) Working in batches, gently pour or ladle the concentrate through the lined strainer, using a flexible spatula to gently scrape the bottom of the cheesecloth as necessary to pass the liquid through.

Step 4

Make the cold-brew coffee: When ready to serve, in a large glass filled with ice, combine the cold-brew concentrate with the water or milk. (If using water, add milk or half-and-half, to taste, if desired.)