1/2 pound dark roast ground coffee
8 cups cold water
1/2 teaspoon vanilla extract
1 14-ounce can sweetened condensed milk
Stir together ground coffee and 8 cups cold water in a pitcher until well combined; let stand at room temperature 12 hours.
Pour coffee mixture through a large, fine wire-mesh strainer into a Dutch oven or other large container, discarding grounds.
Clean strainer; place a coffee filter or double layer of cheesecloth in strainer, and pour coffee mixture through lined strainer into a pitcher. Add vanilla extract. (You can cover and store the coffee in the refrigerator up to one week, if desired.)
Stir together coffee mixture and sweetened condensed milk and serve over ice.