Place 10 fresh mint leaves and 0.75 oz simple syrup into a sturdy Collins or highball glass. Use a muddler (or handle of a wooden spoon) to gently press and twist the mint against the glass bottom for about 10–15 seconds until fragrant. Avoid pulverizing the leaves — you want oils, not bitterness.

Add lime

Pour in 1 oz fresh lime juice and give the mint-syrup mixture one quick stir to combine and lift oils into the liquid.

Add rum & ice

Add 2 oz white rum, then fill the glass with about 1 cup crushed ice, leaving ~1/2 inch headroom.

Top & build

Pour 2 oz chilled club soda over the ice. Using a long bar spoon, gently fold/stir the drink 6–8 times from bottom to top to integrate without flattening the soda.

Garnish & serve

Slap a mint sprig between your palms to release aroma, tuck it into the glass with a lime wedge on the rim. Serve with a short straw and enjoy immediately.

Batch Method (makes 6 cocktails)

Prepare mint & syrup

In a large pitcher, add 60 mint leaves and 4.5 oz simple syrup. Gently muddle the leaves into the syrup using a muddling tool or wooden spoon — press to release aroma but do not shred leaves.

Add lime and rum

Stir in 6 oz fresh lime juice and 12 oz white rum until combined.

Chill & strain

If you prefer a cleaner appearance, let the mixture sit 5–10 minutes then strain into a second pitcher to remove most mint leaves (reserve some lightly torn leaves for garnish). Keep chilled.

Assemble cocktails

To serve, fill six Collins/highball glasses with 1 cup crushed ice each. Divide the batch mixture among glasses (about 3 oz mix per glass), top each with 2 oz club soda, stir gently 6–8 times, and garnish with a lime wedge and mint sprig.