Make the refresher base: Stir together water, mint leaves, grape juice, and sugar in a medium saucepan. Bring to a simmer over medium heat, then simmer for 5 minutes.
After 5 minutes, remove from heat and allow the mixture to cool and steep at room temperature for 15 minutes.
After 15 minutes, strain out the mint leaves, squeezing them to get as much liquid as possible. Reserve the liquid, and discard the mint leaves.
Transfer the liquid to a large jar with a lid, and stir in the fresh lime juice. This is your refresher base. Allow to cool completely in the fridge before using.
Make the refresher: Stir together ½ cup Cool Lime Refresher Base and ½ cup water, then pour over ice. Garnish with fresh mint leaves and/or lime slices and drink up!
