Vermouth is a fortified wine, a wine that has had alcohol added to the wine, in this case, usually brandy. Vermouth is typically made with white grapes and flavored with herbs. Vermouth was inspired by the practice of creating "tonics," wines mixed with herbs of various sorts as a household practice. While the specific formula, and herbs used depends on the maker, the name vermouth itself is from French vermout, derived from German wermut, itself from Middle High German wermuot, or "wormwood," from Old High German wermuota. Vermouth, in other words, was originally made with wormwood. Modern vermouth does not use wormwood; instead, the manufacturers use cardamom, chamomile,cinnamon, and marjoram, among others, as additives to wine lightly fortified with unaged brandy, and varying degrees of sugar. In fact, what we know about the origins of vermouth suggests that the name was chosen simply because the 1786 originator, one Antonio Benedetto Carpano of Turin, Italy, was inspired by a German wine that did use wormwood. While the Carpano family no longer owns the winery, the Carpano brand still exists, producing. Carpano still produces two types of vermouth: the sweet "Original Torino Vermouth" sold as Carpano Antica and based on the original recipe, and Punt e Mes Vermouth, which is more aromatic and bitter.

The next large scale Vermouth maker was Noilly Prat. Noilly Prat was first developed by Joesph Noilly in 1813; Noilly was an herbalist in France. His was the first of what would now be described as a dry Vermouth; which is why today dry, paler Vermouth is often called French. The family moved the company to Marseillan. Even now, they still use locally grown white Picpoul de Pinet and Clairette grapes. In addition to the traditional dry vermouth, they also produce a red, sweet variety of Vermouth, largely for export to the U. S. Their amber Noilly Prat Ambré is only available at the Noilly Prat onsite store in Marseillan, and features cinnamon and orange peel. Noilly Prat was purchased by by Martini & Rossi in 1971 and is now a part of the Bacardi-Martini family of brands. The Cinzano family began producing their Vermouth in 1816. Currently Cinzano Vermouth is produced in four varieties. Cinzano Rosso, the original recipe is an amber colored Vermouth, and the most popular. Then there's Cinzano Bianco, a white Vermouth that is drier than Rosso, but is still a sweet Vermouth. Finally, Cinzano Extra Dry, and the relatively new Cinzano Roséthis is a very different Vermouth with orange overtones and flavored with roses. Martini & Rossi, now the largest manufacturer of Vermouth, started production in 1863. Martini & Rossi Vermouth still dominate the market for Vermouth in the United States.

In 1999, Quady Winery in California began producing both sweet and extra dry Vermouth made from orange muscat grapes, and sold under the Vya label. Their mission, and they do see it as a mission, was to produce a high quality vermouth, one that could enjoyed on its own as an apéritif, and a high quality dry Vermouth, suitable for mixed drinks using top-shelf vodka and gin.

Modern Vermouth is available in several styles, ranging from the very driest to the sweetest. Extra dry (usually around 18% alcohol or 36 proof), bianco or white, and sweet or red Vermouth, sometimes called russo, and typically taking its color in part from the caramelized sugar used to make it. The alchohol level is around 15% to 16%, or 30 or 32 proof. Older recipes will sometimes refer to sweet vermouth as Italian Vermouth, and dry Vermouth as French Vermouth, irrespective of the country of origin.

By the late 1800s Vermouth was the nineteenth century equivalent of vodka in popularity; all sorts of drinks called for it. Sweet Vermouth is frequently enjoyed on its own, or on the rocks as an apéritif, and in mixed drinks (the Manhattan in particular), while dry Vermouth is a central ingredient in a good martini. Martini & Rossi Rosso is the usual vermouth for mixed drinks calling for a sweet vermouth.

The most famous vermouth cocktail is the gin Martini, typically made with dry vermouth, and increasingly, with the vermouth more hinted at than used in measurable quantities. Many favor Noilly Prat Extra Dry for a dry martini. Personally, I think it's a bit of a shame when the vermouth is essentially misted into the glass by an atomizer then wiped off. The custom of rinsing the glass with a tablespoon or so of Vermouth is quite different; there the Vermouth is meant to enhance and flavor, rather than overpower. The Manhattan, traditionally made with American Rye, also calls for sweet vermouth, bitters, and ice. There are Manhattan fans who are downright adamant that Carpano Antica Vermouth is the only one to use in a Manhattan; others are equally adamant about Carpano Punt e Mes in a Negroni made with rye (traditionally the Negroni is made with gin). An older Vermouth based cocktail that, in my opinion, is due a comeback is the Duplex; 1.5 ounces dry Vermouth 1.5 ounces sweet Vermouth, two dashes orange bitters, mixed and poured over ice (or, if the Vermouth is chilled, you might skip the ice) and served in a rocks glass with a lemon twist as a garnish.