Method
Place the lime wedges and sugar in a highball glass. Muddle firmly for 10 seconds — you want the juice out and the sugar dissolved, but the lime rind intact.
Slap the mint leaves between your palms (don't muddle them) and drop them in. Fill the glass with ice.
Add the rum if using. Top with club soda. Stir once with a barspoon to lift the mint from the bottom.
Garnish with a mint sprig. Serve with a straw and a long-handled spoon.
Slap the mint, don't muddle it. A muddled mint is a bitter mint.
The mojito is the most popular drink in Cuba and one of the most poorly made in the world. The two mistakes are: over-muddling the mint (it turns bitter) and using a simple syrup that drowns the lime. We use a 1:1.5 sugar-to-water syrup (less sweet than the standard 1:1), muddle only the lime (not the mint), and slap the mint before dropping it in. The result is a drink that tastes like a garden in a glass — green, bright, and clean. With or without rum, the structure works. The rum version is a mojito; the rumless version is what we call a 'cooler'.