Agua de jamaica

Step 1: Put 2 ⅛ oz dried hibiscus flowers in a sieve and rinse under cold water, rubbing gently, to wash off dust and any grit from drying.

Step 2: Bring 750 ml of 3 ¼ cups water to the boil in a saucepan with 1 cinnamon stick.

Step 3: Add the flowers and simmer for 5 minutes over a medium heat. The water turns deep red almost at once. Don't boil longer: long boiling pulls out harsh tannins and makes the drink taste stewed.

Step 4: Take the pan off the heat and stir in 5 ½ oz caster sugar until dissolved. Sugar dissolves easily now, while the concentrate is hot, and won't later.

Step 5: Leave to steep for 20 minutes, until the liquid is deep crimson and almost opaque. Don't leave it for hours: it turns bitter.

Step 6: Strain through a sieve into a large jug, pressing on the flowers to get all the liquid out.

Step 7: For a lighter second batch, steep the used flowers in 300 ml boiling water for 10 minutes and strain into the jug. Then discard them, or eat them in tacos (they taste like tart cranberries).

Step 8: Add the rest of 5 cups water, cold, and 1 lime. Taste: it should be tart and fruity, not sour or syrupy. Add sugar or water to your liking; it tastes less sweet when ice-cold, so make it a touch sweeter than you think.

Step 9: Chill for at least 1 hour. The concentrate (before diluting) keeps 2 weeks in the fridge, so you can make a big batch and dilute it as you go.

Step 10: Serve in tall glasses over 1 ⅛ lb ice cubes with a sprig of 4 sprigs fresh mint. The diluted drink keeps 4–5 days in a covered jug in the fridge. Hibiscus stains, so wipe up spills quickly.