These fruit coolers, made with fresh pineapple, lime juice, and mint leaves, are a refreshing way to combat summertime heat. They are equally delicious with or without the addition of white rum.
Stir 2 quarts water, the sugar, mint, lime juice, and rum, if using, in a large pitcher.
Feed pineapple through an electric juicer. Strain juice into pitcher; discard pulp. Refrigerate until ready to serve, up to 1 day.