Bitters are highly scented and flavoured mixtures of varying alcoholic strength. Aromatic bitters are used as aperitifs and digestifs. Flavouring bitters are used to add flavour to various drinks, such as cocktails. Most bitters of repute are made from formulae which are kept closely guarded secrets. Bitters are the result both of infusion and distillation processes applied to aromatic plants, seeds, herbs, barks, roots, and fruits, all carefully blended on a spirit base.
Bitters are usually sold under the name of the substance that has been used to give the predominant flavour, such as orange or peach bitters. The best known bitter is probably ANGOSTURA.