Using what I had, this turned out much more moreish than I'd anticipated - Salers, 2:1 blend of Cocchi Americano to Punt e Mes, and Fever Tree Light tonic water. Bold, blush, and bitter up front, drying out in the aftertaste... If this was batched and bottled commercially, I might buy it by the case.
Very nice and refreshing gentian cocktail! I used Bonal in place of Byrrh, and found the base (Suze and Bonal) to be very nice on it's own, but really liked the effect of tonic water - diluting the drink and adding a bit of quinine bitterness.
Thanks, I much appreciate expanding on low alcohol drinks like this one. Schweppes tonic did a good job — the crispness suits it well. One basil top was also an excellent complement. I also agree that it is absolutely possible to play with proportions here — Byrrh and tonic is an excellent combo on its own!