In a small saucepan, bring wine, 1 1/4 cups water, and sugar to a boil over medium heat, stirring often, until sugar dissolves. Add pears; reduce heat, and simmer until tender, 5 to 10 minutes.
Stir in lemon juice and a pinch of salt; cool completely. Transfer to a shallow baking dish. Freeze until solid, about 6 hours (or overnight).
With a fork, break frozen mixture into large pieces. In two batches, puree in a food processor until completely smooth, 2 to 3 minutes per batch. Transfer to an airtight container; freeze until ready to serve (sorbet will be soft).
You can use 1 cup cranberry-juice cocktail instead of the red wine.