- Combine sugar and water in a small saucepan and bring to boil, stirring constantly until sugar is completely dissolved.
- Remove from heat and add thyme sprigs. Cover and let cool for 10-15 min.
- Strain into small jar/bottle and store in fridge. (Double this recipe and use extra within 1 month.)
- In a large pitcher, combine syrup, rum, lime juice, and bitters. Stir well.
- Pour into ice-filled rocks or mule glasses and top with a splash of soda, sprig of thyme, and slice of lime.