Place the ground coffee in a 28-ounce Mason jar, or similar. Add the water, then stir. Cover and set aside for 12 to 24 hours at room temperature.

Spread a piece of cheesecloth or paper coffee filters in a fine mesh strainer and place it over a large bowl. Pour the coffee into the bowl to strain it. Store the strained coffee in the fridge for up to a week.

When ready to serve, pour 3/4 cup of the concentrate over ice. If the coffee is stronger than you'd like, dilute it with water or milk, as desired. I like a 1:1 ratio of cold brew concentrate to extra water or milk. Feel free to adjust the ratios to your liking, adding more coffee, water, and/or milk to taste.