Place sumac berries in cool/room temperature water - I recommend 1 large berry cluster per 2 cups of water at a minimum. The more sumac you use the less time it will take to create flavorful sumac-ade
Crush or break apart the berry clusters in the water
Allow to soak for a few hours to a few days, depending on how much sumac you used and how strong you'd like your sumacade
Strain your extract through cheesecloth or similar fine mesh fabric
Sweeten to taste
Serve over ice for a refreshing beverage!
Notes
You can create a concentrated extract to be used in place of lemon/lime juice in recipes by soaking several batches of sumac in the same water. When the extract tastes similar in acidicity to lemon/lime it's done.