This recipe is one of many for this floral spritz and some may prefer to follow the standard 3:2:1 Spritz formula with 60ml prosecco, 40ml elderflower...
I make it as a conventional Spritz with 3:2:1 ratio, but as I make large Spritz (180:120:60) I change the St Germain element to half St Germain and half Lilet blanc. It reduces the sweetness whilst still maintaing the distinctive elderflower notes, and the Lilet gives it a little more Ooomph.