A word about vermouth:
I always thought that dry vermouth came from white grapes, while sweet vermouth came from red. It turns out, however, that the rich auburn color of sweet vermouth actually comes from caramel. This is reflected in the brownish tinge that it often gets when mixed with lighter ingredients, and in its slightly creamy sugary flavor. It is sometimes called "Italian" vermouth, to differentiate it from "French," or dry vermouth.
Both dry and sweet vermouth are fortified with brandy and flavored with a wide variety of herbs, spices, and flowers. In the beginning, one of these herbs was wormwood, the active ingredient in absinthe. "Vermouth," in fact, is a French derivation of "Vermut," the German word for wormwood. In addition to its name, wormwood also gave vermouth a reputation as an aphrodesiac, a link that continues forth to today's martinis.
Supposedly, vermouth no longer contains wormwood; however, given the secrecy of its ingredients, it's hard to tell what, exactly, goes into the mix. Taken straight, it tends to have a slightly funky, vegetal flavor that isn't really all that pleasant. However, mixed into other drinks, it often blooms, offering a complexity that can be pretty delightful.
For some reason -- I'm not sure why -- drinks that contain equal parts sweet and dry vermouth are often referred to as "perfect." For example, a perfect martini contains sweet vermouth, dry vermouth, and gin. Today's drink, the Addington, could also be classed as a perfect cocktail.
In truth, however, the "perfect" title may be a mite extravagant. After the ice melted and the orange twist melded, this turned into a good drink; initially, though, the vermouth flavor was strong and way too funky. It might be nice with a splash of fresh orange juice, but that is probably another drink altogether...
(from The Ultimate A-to-Z Bar Guide
1 1/2 ounces sweet vermouth
1 1/2 ounces dry vermouth
cold club soda
orange or lemon twist
Pour vermouths into chilled highball glass filled with ice cubes. Top with club soda, stirring lightly. Drop in orange or lemon twist.