A fortified wine that some historians date back to the time of Hippocrates, when it was used as a medicinal. The word "vermouth" comes from the German wermut or vermut ("wormwood") which, before it was declared poisonous, was the principal flavoring ingredient. Today's vermouths are flavored with a complex formula of myriad botanicals including herbs, spices, flowers and seeds, the exact recipe depending on the producer. There are two primary styles of vermouth sweet (red) and dry (white). All vermouths are derived from white wines. Sweet vermouth was introduced in 1786 by Italian Antonio Benedetto Carpano. It has a slightly sweet flavor and a reddish-brown color from the addition of caramel. This Italian-style vermouth is served as an apéritif and used in slightly sweet cocktails like the americano. Dry vermouth, created by Frenchman Joseph Noilly in 1800, is also called French vermouth, although today it's also produced in other countries including Italy and the United States. Dry vermouth is served as an apéritif and used in dry cocktails like martinis. Drinks made with half sweet and half dry vermouth are referred to as "perfect," as in a perfect manhattan. A vermouth's flavor begins to dissipate as soon as it's opened so it should be stored in the refrigerator for no more than three months.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.