From late summer to early fall is an ideal time to make a cold infusion of sumac berries for a refreshing lemonade-flavored tea. Simply gather ripe red berry clusters from any sumac tree (poison sumac has white berries and overall looks very different, so it's difficult to make a mistake and accidentally gather these). To ensure you aren't wasting your time, touch your tongue to a berry cluster. If nice and sour, they are ripe. They are best (prime sourness) when glistening with a whitish sap. Try to harvest before a heavy rain.
Next, simply place berry clusters in a jar and cover with cold water. Wait for anywhere between 1 hour and a day. Strain and sweeten to your liking with your favorite sweetener. We used a simple sugar syrup. Cool in the fridge, and enjoy after chopping firewood or any tough, hot outdoor chore, or whenever you'd reach for a refreshing glass of lemonade.