Mix the grapefruit juice and lemon juice with the brown sugar and coconut blossom sugar in a saucepan. Peel and roughly chop the ginger and add. Bring everything to the boil and simmer for 15-20 minutes.
Filter out the ginger and pour the syrup into boiled bottles. I took bottles that fit about 300 ml and was able to fill 3 bottles. Put a sprig of thyme in each bottle, close and refrigerate.
Simply bring the black tea to the boil. I cook it completely without sugar. If you like it sweeter, you can also put sugar in there.
For the iced tea itself, simply mix 1/3 syrup with 2/3 black tea and fill the glass with ice cubes. Serve garnished with grapefruit slices and thyme.
Optional: If you want the iced tea with a little twist, you can pimp it with a little gin. Gin tastes wonderful with it.