Why Do You Stir Some Drinks and Shake Others?
The debate of shaken versus stirred drinks is hot, especially when you’re looking through cocktail recipes you’ll see some are shaken, some stirred, but is there a theory behind which method to choose? Yes, there is a general rule (as rules go in bartending). There are always exceptions to this rule so it is best to follow a recipe’s instructions or, why not, experiment with both.
Shaking is generally best with flavorful and/or thick mixers (fruit juices, simple syrup, egg/dairy, simple syrup, etc.) and stirring is best with cocktails using distilled spirits or light mixers. This is mostly because the thickness of the mixer determines the force necessary to combine it with the alcohol.
For aesthetic purposes, shaking also tends to create a cloudy look which will turn more translucent once strained. Stirring, however, will give you a more precise amount of dilution. Stirring is also slightly “safer,” as shaking can result in bruising the alcohol.
The two techniques, however, are not identical. Stirring is a delicate process that slowly chills the glass. The slower cooling also means slower dilution. A common mistake is stirring too little, resulting in a luke warm drink without sufficient dilution; a good 60 seconds of stirring should be sufficient.
Shaking is much more violent, and the increased surface contact cools the drink much faster. As few as 10-15 seconds of shaking is equivalent to a full minute of stirring, and people often shake too much leaving the drink too dilute.
So why not shake every drink and save all that time? The violence of shaking also aerates the drink, creating small bubbles that change the way the drink settles on the tongue and rendering the drink opaque. The bubbles will eventually settle to the surface and disappear, but not before the drink has warmed too much.
The rule of thumb is to stir any drink that is meant to be translucent, Martinis and Manhattans for example, and shake anything that already has an opaque ingredient like citrus. Incidentally, stirring a usually shaken drink can produce some interesting flavors.