In the sauce pan, bring the sugar and water to a boil over medium high heat, just until the sugar dissolves. Remove from heat.
Add the lemon thyme leaves and lemon zest. Allow to sit for 10 to 15 minutes, until the flavors are infused. Stir in the fresh lemon juice.
Allow to cool to room temperature. Transfer to the plastic container, then cover and refrigerate overnight.
Freeze according to the manufacturers directions for your ice cream freezer. The sorbet will be soft when finished. You can transfer to a freezer container and freeze for another hour or two before serving if you prefer a harder consistency.