Use coarsely ground coffee
Add coffee to a jar or pitcher
Use a coffee-to-water ratio of about 1:4 to 1:8
Pour cold or room-temperature water over the grounds
Stir gently to make sure all grounds are wet
Cover the container
Let it steep in the refrigerator or at room temperature for 12 to 24 hours
Strain the coffee through a fine mesh sieve, cheesecloth, or coffee filter
Discard the grounds
Dilute the concentrate with water or milk if needed
Serve over ice or store in the refrigerator