Angostura bitters are a concentrated bitters product (high-proof) built around gentian and a proprietary blend of spices and botanicals. It’s intensely aromatic—think clove, cinnamon, allspice, and dark baking spice—used in dashes, not pours.
It doesn’t read as “sweet” on its own; it reads as structure. In drinks it adds dryness, spice, and a tightening effect that makes spirits taste more dimensional and “finished,” especially in classics like an Old Fashioned or Manhattan.