This was just an attempt to take something more exciting to a bottle of wine to a gathering, and it wound up being a hit. This is another soda siphon cocktail that can be pre-mixed and pre-carbonated, although I have included single-serving amounts as well in italics.
100 ml (1 oz) white tequila
100 ml (1 oz) lavender-infused vodka
100 ml (1 oz) apricot-mint syrup
50 ml (1/2 oz) Cointreau
50 ml (1/2 oz) Aperol
50 ml (1/2 oz) lime juice
500 ml (5 oz) water/soda water
Pour into a soda siphon (if using), carbonate and let refrigerate for at least 4 hours. To serve, pour over ice in a tall wine glass. Garnish with whatever citrus or berries are at hand.
The name of this one came to me as a description of its final taste, though I then had to explain that there wasn't really any grapefruit in it. If bringing this to a party, I recommend dispensing it slowly into a clean 1-liter bottle (preferably with a stopper-top) which makes transportation easier and preempts the foam you get when serving directly from the siphon.
If you're in a pinch, you could substitute St. Germain for the lavender vodka and an apricot liqueur (Rothman & Winter the best choice) for the syrup, although you will have a slightly stronger final product.