This coffee is mellower and less acid than hot brewed. You don't need a special machine to make it. Mix 1 ounce (a little less than 3 tsp.) coarsely ground coffee beans with 8 ounces cold water in an airtight container like a mason jar. Refrigerate 12 to 24 hours. Strain through a filter and drink hot or iced. Compost the filter and grinds.
Note: I tripled the recipe
Source: Redbook Magazine