Add the coffee and water to a container with a lid, then give it a good stir.
Cover and let sit for at least 12 hours or up to 36 hours. You can brew the coffee at room temperature or refrigerated. If brewing at room temperature, the coffee will extract faster, so a shorter time is better. If brewing in the refrigerator, the coffee will extract slower so you can let it go a little longer.
Place a fine mesh strainer over top of a large bowl, then strain the coffee once to remove most of the coffee grounds.
Discard the coffee grounds,* then place a coffee filter, a few layers of cheese cloth, or a few layers of paper towels inside the strainer set over top of another bowl.
Pour the coffee into the strainer and allow it to drain slowly over the bow. It will take longer to drain this time, so have patience and don't try to force it through.
Once the liquid has finished straining, discard the solids and transfer the liquid to a jar ot bottle and store in the refrigerator for up to a month.
To serve, pour the cold brew coffee over ice and dilute it with a bit of water if desired. Add your favorite sweetener or creamer, then enjoy!