Step 1Combine the hibiscus flowers with 4 cups of water in a medium saucepan and bring to a boil. Boil for 5 minutes, then allow to steep for about 2 hours. Strain and reserve the hibiscus water.
Step 2Place the strawberries in a large bowl, toss with the sugar and macerate for 30 minutes.
Step 3In a blender, puree the strawberries (and any syrup) with the hibiscus water; this may need to be done in batches.
Step 4Strain the mixture with a standard sieve into a large pitcher; stir in 2 quarts water. Adjust consistency as desired with additional water; add more sugar if desired to sweeten. Serve over ice. This will keep for 2 days, refrigerated.