
Gentian liqueur is a French aperitif liqueur of vivid yellow, defined by its core ingredient: gentian root. Sugar is low, so it works structurally more as a bitter than as a classic sweet liqueur.
Gentian bitterness is the point, and the bottles that carry it differ mainly in strength — roughly 16 against 30% — so a swap changes how much alcohol arrives with the bitterness, not the bitterness itself.
Gentian eau-de-vie / Enzian
An unsweetened, clear distillate of fermented gentian roots. It is a high-proof spirit (around 40% ABV), not a liqueur. A direct swap will strip the cocktail of its sweetness and drastically spike the ABV.
In Italian amari gentian is usually one herb among many rather than the lead, and the category rests on a broader bitter-herb bill. An amaro in its place makes the bitterness rounder and more complex; the sharp gentian spine goes.

White Negroni
London dry gin, Gentian liqueur

White Negroni Sour
Navy strength gin, Blanc Quinquina

White Mezcal Negroni
Mezcal

Yellow Twilight
Chamomile cordial

Greenhorn
Tequila blanco

La Tour Eiffel
Cognac

Suzerac
Rye whiskey

Curiosity
Caribbean aged rum

Montreal Cocktail
London dry gin, Canadian rye whisky, Aperitivo, Gentian liqueur