In a large saucepan combine all ingredients and a pinch salt and simmer, uncovered, 10 minutes, or until apples are very tender. Strain mixture through a sieve into a blender and add half of solids in sieve to blender, discarding remaining solids. Puree apple mixture and chill until cold. Freeze sorbet in an ice-cream maker. Sorbet may be made 1 week ahead.