Well, actually, this drink is not limited to France!
It’s been hot for many of us, so here is a “cool” idea:
In France these are known as “syrups” or sirop. Un sirop au citron (lemon syrup) is my favorite on a hot day. Order a Perrier and syrup: oh so… refreshing. They are all good, but somehow the tart lemon just hits the spot.
These, the true Monin brand syrups are not easy to find in this country. I buy mine at Zabar’s in New York: they have a huge selection and are always well stocked. But you CAN buy it on line here and here. Beware: they are expensive to buy on line although you save if you buy in quantity. Try and find a local retailer!
At home I use club soda and then maybe one or two ounces of a syrup. Stir. Maybe add some fresh mint.
P.S. I did go to Zabar’s on line and they only show three flavors. You might try calling them for specifics.