Pour 1/2 cup of the fruit juice into a bowl or heatproof measuring cup.
Sprinkle the gelatin evenly over the cold juice and let it sit for 5 minutes until thick and spongy. Do not stir aggressively; just let it absorb.
Add the remaining 1/2 cup juice and the sugar or honey to a small saucepan.
Warm over low heat, stirring until the sweetener dissolves and the liquid steams gently. Do not boil.
Scrape the bloomed gelatin into the warm juice. Keep heat low.
Whisk gently until completely dissolved and the mixture looks clear and smooth, 1–2 minutes.
Stir in lemon juice (or citric acid) and any extracts. Taste and adjust sweetness or acidity.
Transfer the mixture to a heatproof pitcher for easy pouring, or use a dropper for small molds.
Carefully fill silicone molds. If you don’t have molds, pour into a parchment-lined loaf pan for later cutting.
Refrigerate until set, about 45–60 minutes for small gummies, 90 minutes for a pan.
Pop gummies out of molds. If using a pan, lift out and slice into squares.
Optional: Toss lightly in a mix of sugar and a pinch of citric acid for a tangy coating. Coat just before serving to prevent weeping.
