There is one golden rule to the shake or stir conundrum: Juice! If your recipe contains juice, shake it up. If not, stir it.
The two techniques both work to properly mix your drink, but they're not identical. Stirring is a more delicate process that slowly chills the glass and dilutes your cocktail. A common mistake is stirring too little, leaving you with a warm cocktail without proper dilution. To avoid this, don't be afraid to give your cocktail a good stir! Stirring yields an icy libation that's smooth in texture.
Shaking a cocktail is a bit more vigorous, which cools and dilutes the drink much faster. Juice and alcohol have very different densities, so they don’t mix easily. Shake fast, but make sure to shake hard. This method chills and aerates the cocktail, which creates small bubbles that change the way the drink settles on the tongue. Drinks that are shaken tend to be frothy and light.
Though you can almost always count on our golden rule, every rule has it's exceptions. Sometimes it's best to leave the hard thinking to your bartender, but we can assure you that if a cocktail lacks juice but does involve a whole egg, cream, or espresso, you better get shaking.