Bar Techniques
Shaking versus stirring: As a general rule of thumb, if a cocktail contains fruit (citrus or otherwise), egg, or cream, it should be shaken vigorously. These ingredients are usually viscous and must therefore be integrated into the drink with a good deal of effort. However, if a cocktail is composed mostly of spirit, with vermouth, bitters, or small amounts of sugar or other modifiers, it should be stirred.
Put a different way, if a drink has an ingredient that is cloudy in appearance, it should probably be shaken. If all ingredients are transparent, they should be stirred.
With a shaken drink, you’re looking to liven up the ingredients, creating a slight froth when strained. This is what David Embury, author of The Fine Art of Mixing Drinks, calls the life of the cocktail – you don’t shake it to put it asleep, but rather to wake it up. A stirred cocktail, on the other hand, should have the mouth-feel of extremely cold velvet, smooth but also lush when the ingredients have been properly proportioned and chilled.