Scoop out passionfruit pulp into a bowl. Add tartaric acid and stir to combine.

Add sugar and water to a saucepan and stir over medium-high heat until the sugar dissolves and the mixture is clear. This should take about 5 minutes and the mixture shouldn't boil.

Pour sugar mixture over passionfruit pulp and leave for 15 minutes.

Strain mixture to remove seeds and bottle.

Allow to cool and store in the fridge. You should also be able to store it unopened in the pantry for up to 12 months.

Enjoy mixed with water or soda water, using 1 part cordial and 3 or 4 parts water.