The source of the flavours is fresh wild gentian root from the Auvergne, and fresh cultivated gentian root from Normandy - half of each.
The wild roots take 20 to 30 years to be ready to harvest, while the cultivated variety takes a mere 9 to 13 years. The wild roots are harvested manually with an implement known as "la fourche du diable" - the devil's fork.
The gentler terrain of the cultivated roots can be mechanically harvested, although selection is still entirely manual. The roots are macerated in neutral alcohol for around a year before being pressed to extract the flavour.
The bouquet is enhanced by the addition of a distillate of angelica and other herbs.
Over time the strength of Suze sold in France has declined to 15%, with a consequent reduction in the intensity of the flavours. Suze Saveur d'Autrefois ("taste of the old days") is a return to the original style.