1 1⁄2 oz Blanco tequila
1⁄2 oz Orange juice
1⁄2 oz Lemon juice
1⁄2 oz Lime juice
1⁄2 oz Grapefruit syrup
2 oz Soda water
Shake ingredients and top with the soda water.
Traditionally made with reposado tequila in a cantarito clay cup in Jalisco, Mexico.
Optionally, use grapefruit soda instead of grapefruit syrup and soda.