In a small saucepan combine 1/2 cup granulated sugar and 1/4 cup water. Warm over medium heat, stirring, until the sugar fully dissolves and the mixture is clear but not boiling (about 2–3 minutes). Remove from heat.

Add juice and aromatics

Stir in 1 cup fresh grapefruit juice, 1 tablespoon fresh lime juice and 1 teaspoon grapefruit zest (if using). Mix thoroughly until uniform.

Cool and store

Let the cordial cool to room temperature, then transfer to a clean jar. Chill in the refrigerator — it will keep for up to 7 days. Yield is about 8 ounces (enough for several cocktails).

Assembling the Paloma

Prepare the glass (optional salted rim)

If you prefer a salted rim, rub a lime wedge around the rim of a highball or Collins glass. Dip the rim into a shallow plate of coarse salt to coat. Fill the glass about halfway with ice.

Build the cocktail

Add 2 oz Rancho Alegre tequila, 3/4 oz grapefruit cordial, and 1/2 oz fresh lime juice to the glass over ice. Stir gently with a bar spoon to combine and chill the ingredients (about 5–10 seconds).

Top with soda

Top the mixture with approximately 3 oz chilled grapefruit soda. Stir once gently to integrate without flattening the soda.

Garnish and serve

Garnish with a grapefruit wheel or wedge and a lime wheel. Serve immediately with a straw if desired.