½ cup freshly squeezed grapefruit juice
¼ cup freshly squeezed lime juice
½ cup tequila or mescal
2 tbsp. simple syrup*
½ cup club soda, divided
Rim 2 cocktail glasses with juice from a grapefruit wedge and dip in coarse salt. Fill glasses with crushed ice. Combine the grapefruit juice, lime juice, tequila and simple syrup in a liquid measuring cup or cocktail shaker. Mix well to blend.
Pour ¼ cup of club soda into each cocktail glass. Top each serving off with half of the cocktail mixture. Garnish with grapefruit wedges, if desired.
*To make simple syrup, combine equal parts sugar and water in a small saucepan over medium heat. Heat, stirring occasionally, until the sugar is fully dissolved. Chill before using. Use to sweeten coffee, cocktails, etc.