Measure out 1 cup of coarse coffee grounds.
Combine coffee grounds with 4 cups of cold or room temperature water in a large container.
Stir gently to ensure all grounds are saturated.
Cover the container to prevent contamination.
Let the mixture steep for 12 to 24 hours.
Place a fine mesh strainer or coffee filter over another container.
Pour the mixture through the strainer to separate the grounds from the liquid.
Discard the used coffee grounds.
Transfer the cold brew concentrate to a clean jar or bottle for storage.
Serve by diluting the concentrate with water, milk, or cream to taste, and add ice.