Begin by chopping ripe watermelon into small chunks and placing them in a blender. Blend on high until smooth, about 1-2 minutes.

Pour the blended watermelon through a fine mesh sieve into a bowl, pressing lightly with a spatula to extract as much juice as possible.

In a medium bowl, pour half of the watermelon juice and sprinkle the unflavored gelatin powder evenly over the top. Allow it to sit undisturbed for 5-10 minutes.

On low to medium heat, gently warm the watermelon juice in the saucepan. Stir occasionally, but do not let it boil.

After the gelatin has bloomed, add the mixture to the warm watermelon juice in the saucepan. Whisk continuously until the gelatin fully dissolves.

Once the mixture is smooth, remove the saucepan from heat. Stir in the freshly squeezed lemon juice and honey, if desired.

Carefully pour the gummy mixture into molds or a baking dish lined with parchment paper and place it in the refrigerator to set for at least 2 hours.

Once set, gently pop the sour watermelon gummies out of the molds or cut them into shapes if using a baking dish.