In a small bowl combine fleur de sel, smoked chili powder, tajín and finely grated grapefruit zest. Mix well so the zest distributes evenly and the salt absorbs a little of the citrus oils.

Spread the mixture on a small plate. Rub the serving glass’s rim with a grapefruit wedge or a little lime juice, then press and rotate the rim into the chili-salt mixture until evenly coated. Set glass aside to let the zest settle (a minute).

Hibiscus Syrup (makes ~6 oz)

Make hibiscus syrup

Combine 1 cup water and 1 cup granulated sugar in a small saucepan over medium heat. Stir until the sugar dissolves and the liquid reaches a gentle simmer.

Add the dried hibiscus petals, reduce heat to low, and simmer gently for 5 minutes to extract color and flavor. Remove from heat and let steep 10–15 minutes for a more pronounced hibiscus note.

Strain the syrup through a fine-mesh sieve or cheesecloth into a clean jar; discard the solids. Stir in 1 tsp fresh lime juice if using. Cool to room temperature, then chill. The syrup will keep refrigerated for up to 2 weeks.

Cocktail

Chill: If not already chilled, place the cocktail glass in the freezer for a few minutes or fill with ice water while you build the drink.

Fill a mixing glass or cocktail shaker with ice. Add 2 oz reposado mezcal, 0.5 oz hibiscus syrup, 1 oz fresh ruby grapefruit juice, 0.5 oz fresh pink grapefruit (pamplemousse) juice, and 0.5 oz fresh lime juice.

Stir vigorously for 15–20 seconds (or shake briefly if you prefer a slightly frothier texture) to chill and dilute the drink properly. If you shook, fine strain into the prepared glass over fresh large ice cubes; if you stirred, strain similarly.

Top with 2 oz club soda poured gently to maintain carbonation and create a light effervescence. Give the drink one gentle stir to integrate.

Garnish with a grapefruit twist or dehydrated grapefruit wheel placed on the rim or floated on top. Serve immediately.