Combine 400 ml cold filtered water and granulated sugar in a small saucepan. Add grated ginger and lemon zest. Warm gently over low heat, stirring until the sugar dissolves completely (do not boil) — about 3–4 minutes.

Infuse and cool

Remove the pan from heat and add the packed mint leaves. Cover and let steep 10 minutes off the heat to extract aroma without bitterness.

Strain and sweeten

Strain the infused water through a fine-mesh strainer or cheesecloth into a bowl, pressing gently on solids to extract liquid. Whisk in honey until dissolved, then stir in fresh lemon juice, lime juice, fine sea salt and cold-brew green tea concentrate. If using citric acid, dissolve it in a tablespoon of the mixture before adding to ensure even distribution.

Adjust flavor

Taste and adjust sweetness and acidity: add up to 10 g more sugar or 5 ml more lemon juice to reach the desired balance. The salt should be subtle — it rounds flavors.

Cool completely

Allow the mixture to cool to room temperature, then chill in the refrigerator until cold (30–45 minutes).

Finish with carbonation and bottle

When cold, gently stir in 100 ml sparkling water to add effervescence, then pour into the sterilized 500 ml bottle leaving about 2 cm headspace. Seal the bottle tightly. If you prefer a fully still drink, omit the sparkling water and use 500 ml chilled infusion.

Equipment & finishing

Ensure the glass bottle and cap are sterilized by washing with hot soapy water and rinsing with boiling water or using a dishwasher on a hot cycle. Allow to air-dry on a clean rack.

Label the bottle with the date made. Store refrigerated and consume within 5 days for best freshness. Shake gently before opening; if you used the sparkling water, open carefully to release pressure slowly.