This recipe is used in our Lemon-Thyme Pound Wedding Cake with Meringue Buttercream.
Stir wine, sugar, lemon-thyme, and 1/4 cup water in a saucepan. Bring to a simmer over medium-high heat. Reduce heat to medium-low; simmer 20 minutes.
Pour syrup through a fine-mesh sieve into a bowl; discard lemon-thyme. Let cool slightly, about 5 minutes, before serving. Syrup can be refrigerated in an airtight container up to 1 week; reheat over medium-low heat before serving.