Combine sugar, sparkling wine, lemon peel, apricots, and salt in a medium saucepan over medium-high heat. Bring to a boil. Reduce heat, and simmer for 10 minutes. Remove from heat, and cool. Discard lemon peel. Transfer mixture to a blender; process until smooth. Pour mixture through a sieve over a bowl; discard solids. Cover and chill. Transfer mixture to the freezer can of an ice cream freezer; freeze according to manufacturer's instructions. Scrape sorbet into a freezer-safe container; freeze 2 hours or until firm.