Combine the water and sugar in a small saucepan set over medium heat. Bring the mixture to a simmer, stirring regularly to encourage the sugar to dissolve. Add the sage to the syrup and let it simmer for 3 minutes. Remove the syrup from the heat and cover the pan with a lid to let the syrup steep. Steep for 30 minutes, then strain our the sage and pour the syrup into a bottle or jar. Keep it in the fridge and make sure to use it within 2 weeks. Once you make the syrup, you’ll have enough for 8-10 drinks. 

For each drink, add 1 oz of the sage simple syrup, 1 oz of fresh lemon juice, 1 strip of lemon rind, 2-3 fresh sage leaves, and a dash or two of bitters to a cocktail shaker or mason jar. Fill the shaker with a large handful of ice, then cover with the lid and shake vigorously for 60-90 seconds. Place a few ice cubes in your chosen glass then strain the mixture from your shaker into your glass. Top with 3-4 oz of chilled Topo Chico and garnish with a sage leaf and lemon round if you like. Enjoy immediately!