What is the purpose of shaking a drink before adding carbonation?

The primary purpose of shaking a drink before adding carbonation is to prevent the flattening of carbonation. When you shake a drink that contains ingredients such as spirits, juices, or syrups, you effectively mix them and create a homogeneous blend of flavors. Once shaken, the drink will have a greater volume of bubbles when the carbonation is introduced. If carbonation is added before shaking, the drink may lose its fizz quickly because the agitation from shaking can cause the carbon dioxide to escape more rapidly. Therefore, by shaking first, you ensure that the drink maintains its effervescence when the carbonation is added.

While there are other beneficial aspects of shaking a drink, such as cooling it and mixing the ingredients, the specific focus here is on enhancing carbonation retention by managing how the drink is prepared before introducing bubbles.