Rinse the thyme sprigs and gently clap them between your hands to release aroma. Do not chop or bruise aggressively — thyme turns heavy and dull fast.
Bring the water to a boil, then remove from heat. Add the thyme sprigs and grapefruit peel strips. Cover and let infuse for 8–10 minutes only, just until a strong but clean herbal–citrus aroma develops. Strain out both promptly to avoid bitterness and medicinal notes.
While the infusion is still warm, stir in 2 tablespoons of honey until fully dissolved. Taste and add up to 1 additional tablespoon only if needed. Let the infusion cool to room temperature.
Stir in the fresh grapefruit juice. This provides acidity and a natural bitter–sweet balance. Do not overdo it — this drink is meant to stay sharp and structured.
Refrigerate the base for 1–2 hours until fully cold.
Just before serving, gently stir in the ice-cold club soda. Mix slowly to preserve carbonation.
Fill glasses with ice, pour over the chilled thyme grapefruit sparkling cooler, and garnish with fresh thyme sprigs and grapefruit wedges.
