In her Real Margaritas recipe, Garten recommends blending all the ingredients with ice before shaking the margaritas with more ice, straining, and serving.
Blending creates a smooth base for your margarita and ensures that each sip has a consistent flavor, while the ice mellows the harsher citrus and tequila notes.
This additional step provides two key benefits for the cocktail. Shaking with ice helps to properly chill the drink without further diluting it, keeping the flavors balanced.
Using the shaker before serving the margarita also helps to aerate the cocktail, and the overall flavor profile is enhanced by the oxygen in the drink.