Add 4 cups of water and the dried hibiscus flowers to a small pot. Bring to a boil over high heat, reduce the heat to low, cover, and simmer for 5 minutes.
Carefully pour the hot tea through a strainer or colander into a large pitcher that holds at least 12 cups. Discard the used hibiscus flowers.
Add the sugar and stir until completely dissolved, then add in the remaining 8 cups of cold water.
Taste and add more sugar if desired. You can also dilute it with more water if it’s too strong. Some people like it super sweet, some like it super strong, it's all personal preference.
Serve in glasses over ice and enjoy.
Video
Notes
To make one cup of tea at a time: Follow steps 1-4 to make the hibiscus tea concentrate. Grab a drinking glass and fill it ⅓ of the way up with concentrate and another ⅓ of the way up with water. Stir in 1 teaspoon of sugar at a time until the sweetness is to your liking. Fill the cup with ice and enjoy. Store the remaining concentrate in the fridge for up to 1 week.