medium course ground coffee
coffee filter or sieve
In a jar, stir together 1/3 cup (medium-course grind is best) coffee and 1 1/2 cups water. Cover and let rest at room temperature overnight or 12 hours.
Strain twice through a coffee filter, a fine-mesh sieve or a sieve lined with cheesecloth. In a tall glass filled with ice, mix equal parts coffee concentrate and water, or to taste. If desired, add milk.