The writer and journalist Paolo Monelli defines bitter as " vermouth without wine ." In fact, while the vermouth is flavored wine, the bitter is a flavored liquor , enhanced by plant component and medicinal herbs . The two basic stages for the preparation of the bitter , are those of the infusion and the distillation . The herbs and roots infused undergo a certain dosage and are mixed , then minced , pulverized , immersed in a water-alcohol solution and left to macerate for a long period of several months . The preparation is then decanted to buy clarity and then combined with the liquid from the distillation , ready to make a joint preparation path .