For the Tea Syrup:
- Stir to combine while the tea is still hot, then store in the fridge. Use within two weeks.
Note: the best way to make any syrup is by weight, so if you have a kitchen scale, use it to measure equal parts tea and sugar by weight, not volume.
For the Tea Soda:
- Pour the syrup into a chilled glass, and top carefully with the chilled carbonated water. No need to stir -- the syrup should self-mix as you pour the seltzer in, and stirring will reduce the carbonation.