Run the grapefruit wedge around the outer rim of a highball or Collins glass to moisten. Spread the coarse salt on a small plate, then press the moistened rim into the salt to coat evenly. Set the glass aside.

Mix Cocktail

Fill a cocktail shaker halfway with ice.

Add blanco tequila (2 oz), Aperol (1/2 oz), fresh grapefruit juice (2.5 oz), fresh lime juice (1/2 oz), and simple syrup (1/4 oz, optional if your grapefruit is tart) to the shaker.

Secure the shaker lid and shake vigorously for 10–12 seconds until well chilled (the shaker will frost slightly).

Fill the prepared glass with fresh ice (about 1 cup). Strain the shaken mixture into the glass over the ice, leaving room for soda.

Top gently with club soda (about 1.5 oz) to add effervescence. Stir once gently with a bar spoon to combine the soda with the cocktail without flattening the bubbles.

Garnish & Serve

Garnish the drink with a grapefruit slice or wheel and, if desired, a lime wheel. Serve immediately with a straw or stirrer.

Optional variation: For a stronger grapefruit aroma, express the oils from a grapefruit peel over the drink before dropping it in.