Bring the three cups of water to a boil in a medium pot. Drop the black tea bags into the boiling water and boil for 2 minutes. 

Remove the pot from the burner and steep for 5 minutes. 

Remove the tea bags from the pot after 5 minutes and stir the sugar (if using) into the hot tea until dissolved. Allow the tea to cool to room temperature. Refrigerate it to speed up the cooling process if needed. 

While the black tea is cooling trim the edged off the star fruit points if it is green or bruised.

Slice each trimmed carambola  into star shapes. Use the tip of your knife to pop the seeds out of each slice. Three large starfruit will give you about three cups of carambola slices.

Place the sliced carambola into a blender or food processor. Process the carambola slices about one minute in the blender until the pulp is liquefied. 

Pour the thick carambola juice through a fine mesh strainer placed over a bowl.