Combine juices, water, and sugar in a heavy saucepan and set over high heat.

Stir until the mixture until all the sugar is dissolved, and bring to a slow boil.

Remove from the heat and let cool to room temperature.

Add the Aperol and stir to combine.

Pour mixture into a shallow pan and place in the freezer.

Scrape the frozen mixture with a fork once every hour or so to break it up into smaller crystals.

The granita will take about 4-5 hours to freeze. After it is completely frozen, transfer to a container with a tight fitting lid.