How we tested
Though it's often used in cooking, and even more often in martinis, dry vermouth is a potable that is paid very little attention. Imagine our surprise, then, when we did a little research and turned up nearly a dozen different brands. We pared them down to eight and tasted the vermouths straight (chilled) and in simple pan sauces for chicken (containing only shallots, chicken broth, and butter in addition to the vermouth).
First, a quick description of what dry vermouth is. Its base is a white wine, presumably not of particularly high quality, as evidenced by the relatively low prices of most vermouths. The wine is fortified with neutral grape spirits that hike the alcohol level up a few percentage points to 16 to 18 percent, and it is "aromatized," or infused, with "botanicals," such as herbs, spices, and fruits, (although some large commercial producers use liquid concentrates rather than the botanicals themselves to achieve the characteristic flavor of a dry vermouth). Dry vermouth, also called extra-dry vermouth, is imported from France and Italy (Italian vermouths being most common) or is made domestically in California.
Vermouth has a couple of things going for it. At $5 or $6 for a 750-ml bottle, it's cheaper than most wines. You're also more likely to have an open bottle of vermouth on hand. Because of its higher alcohol content, an open bottle of vermouth will keep longer than an open bottle of white wine; it can be stored in the refrigerator for up to three months. So when you don’t want to open a bottle of wine just to obtain a small amount for a recipe, feel free to use vermouth as a substitute for white wine.