Combine all ingredients, except the sugar, in a large pot.
Gently simmer for about 10 minutes, then remove from heat. Allow the mixture to sit for at least 30 minutes, up to 2 hours to infuse.
Strain the mixture into a glass pitcher. Set in fridge to chill.
When ready to serve, sweeten and/or dilute the mixture to your preference. Serve over ice.
Store unused portion in the fridge for up to 2 weeks. It is normal to see some sediment in the bottle after a few days.
Other flavours you can add are:
For a more "adult" drink, you can add rum to this recipe.
If using fresh sorrel, you will need at least twice the amount compared to using dried sorrel.
To intensify the flavour even more, you can leave the unstrained mixture in the fridge overnight, then strain before serving.
Try lining a sieve with cheesecloth before straining the mixture, this helps to catch tiny particles and impurities in the mixture.
If you don't want to go through the steeping process yourself, look for Sorrel syrup in West Indian or Asian markets.CAUTION: the sorrel mixture is highly pigmented and will stain anything it falls on (clothes, dish towels, plastic etc.).