Combine the water and coffee grounds in your French press. Stir well to fully saturate the coffee grounds.
Cover (do not press down the plunger) and refrigerate for 12-24 hours.
Press down the plunger using firm, steady pressure. Strain the cold brew concentrate into a clear glass jar, pitcher, or other storage container. For a smoother cold brew, you may want to strain it a second time using a paper coffee filter or piece of cheesecloth set in a fine mesh sieve.
Dilute the cold brew concentrate with and equal amount of water, milk, or non-dairy beverage of your choice. Serve over ice.