01 -
Place salt or Tajin on a small plate. Rub a lime or grapefruit wedge along the rim of the glass, then press the moistened rim into the salt or Tajin to coat lightly.
02 -
Add grapefruit juice, lime juice, maple syrup, apple cider vinegar, and a pinch of sea salt to a cocktail shaker or jar with a tight-fitting lid.
03 -
Add 3 to 4 ice cubes. Seal the shaker and shake vigorously for 15 to 20 seconds until well chilled.
04 -
Strain into a tumbler filled with fresh ice. Top with plain or grapefruit soda if desired. Garnish and serve directly.