This cocktail is as simple as it sounds—almost effortless. The key is to use vermouth you genuinely enjoy (I favor dark, robust, earthy Spanish vermouths) and ensure it's well-chilled in the fridge.
- Fill a highball or large wine glass with ice. Pour in the vermouth and then top it off with soda water. You can garnish with a generous wedge of lemon, orange, grapefruit, and perhaps a couple of olives if you like. If you prefer a stronger drink, add a splash of gin.