Vermouth is wine that has been fortified with a neutral spirit and aromatized with botanicals — herbs, bark, citrus, spices, flowers, and roots that vary by producer. It comes in two main styles: dry (French-style, pale, low-sugar, used in Martinis) and sweet (Italian-style, amber, used in Manhattans and Negronis). Vermouth is not just a modifier — it's a complex ingredient with its own character. It should be refrigerated after opening and used within a month or two; stale vermouth ruins drinks that are otherwise excellent.
Why It Matters
Vermouth is the ingredient most consistently used badly. It's treated as an afterthought — a splash of something from a bottle that's been sitting in a cabinet for two years. Used fresh, in the right ratio, and from a good producer, vermouth transforms a spirit into a cocktail. Carpano Antica Formula sweet vermouth and Dolin dry vermouth are reference points.
Where You'll Use It
Martini (dry vermouth), Manhattan and Negroni (sweet vermouth), Bamboo and Adonis (both styles). In AF applications, a good non-alcoholic vermouth substitute adds the floral, herbal bitterness that vermouth contributes.