You may be surprised to hear that Vermouth is technically wine. It's categorized as a fortified wine, meaning some type of spirit is added to it to manipulate the flavor, and in this case, different herbs and spices as well. Which herbs and spices are added depends on the variety, sweet or dry. Similar to gin, each brand has its own recipe for which additives they include. Vermouth is often added to cocktails to add a herbal flavor though it can also be sipped alone as an aperitif.