What is commonly added to a martini to enhance its flavor?

The addition of dry vermouth to a martini is a classic technique that enhances its flavor profile. Dry vermouth is a fortified wine that has been flavored with a variety of botanicals, resulting in a complex and aromatic undertone when mixed with the primary spirit, typically gin or vodka. This infusion adds depth and sophistication to the drink, balancing the pure alcohol with herbal notes and subtle sweetness, which is essential for achieving the traditional taste of a martini.

In contrast, sweet vermouth is typically used in cocktails like a Manhattan, where its richer profile complements the other ingredients. Fruit juice tends to be too sweet and overpowering for a classic martini, while simple syrup introduces unnecessary sweetness that can mask the refined flavors of the gin or vodka. Thus, dry vermouth is the preferred choice among bartenders for enhancing the flavor of a martini.