In a medium glass or metal pitcher, combine the ground coffee and the water. Stir well to moisten all of the coffee grounds.
Cover and let the mixture sit at room temperature for 12 to 24 hours. (A longer brew time will result in stronger coffee.)
Set a fine mesh strainer over a large measuring cup or bowl, and line it with cheesecloth or a coffee filter. Slowly pour the coffee mixture into the filter to strain out the grounds. (You may need to do this in stages, allowing time for the brewed coffee to drip through the filter before adding more.)
Store the cold brew in a jar or airtight container in the fridge for up to 1 week. Serve it over ice and add the sweetener or creamer of your choice, if desired.
Notes
Use cheesecloth with a fine weave. Some types are loose or openly woven. A tighter weave will make sure to catch all of the grounds and sediment from the coffee beans.
You don’t need to brew the coffee in the fridge, but if you’d prefer to brew more slowly and for longer, you can place the water and coffee grounds in the fridge to brew for up to 36 hours.