1 cup fresh mint leaves
3 cups ice
3 cups freshly squeezed red grapefruit juice
2 cups ginger ale
1 Put the mint into a large bowl or sturdy jug, using the end of a rolling pin, muddle or squash the mint.
2 Pour the red grapefruit juice over the mint and stir to combine.
3 To serve the julep, fill four glasses with ice and fill with juice mixture to two thirds capacity and top with ginger ale.
4 Serve with straws, stir just before drinking.