01 -
Spread a small amount of salt or Tajin on a shallow plate. Run a lime or grapefruit wedge along the rim of each glass, then dip the moistened rim into the salt or Tajin, pressing gently to adhere.
02 -
Add grapefruit juice, lime juice, maple syrup, apple cider vinegar, and a pinch of sea salt to a cocktail shaker. Add 3 to 4 ice cubes and seal tightly.
03 -
Shake the shaker vigorously for 15 to 20 seconds until well chilled and thoroughly mixed.
04 -
Strain the mixture into a tumbler over fresh ice. Top with soda water or grapefruit soda if desired.
05 -
Garnish with a wedge of lime or grapefruit and serve immediately.