Big-Batch Margaritas

Heat 14 ounces water, 1 cup plus 2 tablespoons sugar, and ⅛ teaspoon table salt in medium saucepan over medium heat, stirring often, until sugar has dissolved, about 2 minutes; do not boil. Off heat, stir in 1 tablespoon grated lime zest and 1 tablespoon grated lemon zest and let cool completely, about 30 minutes. Strain citrus syrup through fine-mesh strainer into bowl, pressing on solids to extract as much liquid as possible.

Combine citrus syrup, 24 ounces blanco or reposado tequila, 9 ounces orange liqueur, 6 ounces lime juice, and 6 ounces lemon juice in serving pitcher or large container. Cover and refrigerate until well chilled, at least 2 hours or up to 24 hours.

Stir cocktail to recombine. Spread ½ cup kosher salt, if using, into even layer on small saucer. Moisten about ½ inch of chilled rocks glass rims by running lime wedge around outer edge; dry any excess juice with paper towel. Roll moistened rims in salt to coat. Remove any excess salt that falls into glasses. Serve in prepared glasses filled with ice, garnishing individual portions with lime slices.