Combine the brown sugar and water in a small saucepan and heat gently over medium heat, stirring continuously until the sugar fully dissolves into a smooth, lightly caramel-colored syrup. Do not allow the mixture to boil or reduce — excessive heat concentrates sweetness and dulls the subtle molasses depth that gives the mocktail its rounded, cocktail-like character. Remove from heat and let cool completely before using.

Rinse the fresh mint leaves under cold water and pat them dry. Gently clap the leaves between your palms or lightly press them with your fingers to release essential oils. Avoid chopping or aggressive muddling — the goal is aromatic lift, not vegetal bitterness. Let the prepared mint rest for a minute so its fragrance opens up fully.

In a large pitcher, combine the fresh lime juice, measured brown sugar syrup, white verjus, mint leaves, and a small pinch of fine sea salt. Stir slowly until the mixture becomes homogeneous and aromatic. Allow the base to sit for about 5 minutes so the mint oils and citrus acidity integrate. Taste and adjust carefully — the liquid should feel slightly sharper and more intense than the final drink will be after dilution.

Fill the pitcher generously with ice to begin gentle dilution and chilling. Pour in the ice-cold club soda last and stir once or twice only to integrate. Overmixing will drive off carbonation and flatten the drink’s lively texture, which is essential to its refreshing character.

Pour the virgin mojito into ice-filled glasses and garnish with fresh mint sprigs and lime wedges. Serve fully chilled while bubbles are active and aromas are bright.