Subsequently, I tried
Since then, I have been experimenting with some of the tisanes from my cupboard. I’ve found with these that I need to use more teabags to get to a decent strength overnight, but still only 4-5 for a large jug (1.5 litre), so it is still very economical compared to other cold drinks and cordials, and practically zero calories too.
The big favourite at the moment is Twining’s Lemon and Ginger. I’ve found 4 bags in my jug, left for 8-10 hours, makes a very pleasant straw coloured drink that tastes distinctly of ginger. The lemon is a little more subtle, but is there. It is exceedingly thirst-quenching, especially straight out of the fridge.
I may never buy cordial again!