Add ½-¾ cup of the juice to a bowl or liquid measuring cup and sprinkle with gelatin powder.
Whisk together to combine and allow to sit for 3-5 minutes to “bloom.” The granules will plump and the mixture will look like very thick applesauce or take on a lumpy appearance.
Pour the remaining (3 ¼- 3 ½ cups) juice into a medium saucepan. Heat over medium heat until almost boiling.
Remove from heat and stir in honey (if using) and the bloomed gelatin mixture. Stir to dissolve.
Pour into an 8×8 (2 quart) baking dish for thick Jello or a 9×13″ baking dish for thin Jello, or into individual glasses or jars for individual portions.
Refrigerate about 4 hours, or until set. (If you’ve used a 9×13 pan, it may be set in as little as 2 hours)
