In a small, nonreactive saucepan combine the wine, sugar and lemon juice. Bring to a simmer, stirring to dissolve the sugar, and cook briskly for 2 minutes. Remove from the heat and cool to room temperature.
In a food processor or blender, puree the pears until smooth. In a storage container with a tight fitting lid, thoroughly stir together the pear puree and the cooled wine mixture. Cover an freeze until solid, preferably overnight.
Using a large spoon, scrape the granita, as much as you’d like to serve, and scoop into bowls. Serve immediately. You can keep the leftover granita frozen until ready to eat.