In a small saucepan combine the cranberries, sugar, and water and heat until sugar dissolves, about 5 minutes. Let cool about 20 minutes.

To a jar add the cranberry syrup and the moonshine, stirring to combine. Cover and let the moonshine infuse for three days at room temperature. Strain through a fine-mesh strainer, discarding the cranberries. Transfer the moonshine to a clean jar and keep in the fridge for up to 2 months.

In a glass filled with ice combine the moonshine with ginger ale. Garnish with a lime if desired.