For a "Perfect" martini, how much dry vermouth is used?

In a "Perfect" martini, the correct amount of dry vermouth used is typically 1/4 oz. This specific proportion combines both dry and sweet vermouth, creating a balanced flavor profile that distinguishes a "Perfect" martini from other variations.

When crafting this cocktail, the use of both types of vermouth—dry adds a crispness while sweet rounds out the flavor—results in a more nuanced drink. The classic "Perfect" martini showcases the delicate interplay between the botanical notes of the gin and the subtle sweetness of the sweet vermouth, which is why the correct measurement of the dry vermouth is crucial to achieving that desired balance. Using 1/4 oz allows for this harmony while still keeping the drink predominantly focused on the gin, which is the star of the cocktail.