Fill a cocktail shaker or small pitcher with ice. Add the bourbon, cranberry juice, lemon syrup, and bitters. Cover and shake vigorously until thoroughly mixed and chilled, about 30 seconds. (In general, the drink is ready by the time the shaker mists up.) Strain into a chilled cocktail glass. Drop 2 to 3 cranberries in the glass. Drink.
Put the lemon wedges, sugar, and water into a saucepan; bring to a boil, stirring occasionally. Reduce heat and simmer for 15 minutes. Cool and refrigerate for up to 2 weeks.