Soften the gelatin in 100 ml of water (not listed).
If using fresh grapes, peel. If using canned, drain. Put the grapes in the containers you'll be using for the jello.
Put the sugar in a pan. Adjust the amount of sugar to taste! Put in a little to begin with; you can add more (at Step 6 or so) later!
Add 1/4 to 1/3 of the grape juice to the pan and mix lightly. Heat until it's about 50 °C. Don't let it boil, it should be just hot to the touch.
Add the softened gelatin from Step 1 to the pan, and mix well to dissolve. Turn off the heat and dissolve the gelatin with in residual heat.
Add the rest of the grape juice as well as the red wine.
If serving the jello to children, swap the wine for more juice, or bring the wine to a boil separately to evaporate the alcohol.
Pour the liquid into the prepared containers, and chill until set.
Story Behind this Recipe
When I made Recipe ID: 1526493 "Slippery jelly made with Agar", I made a gelatin version, that calls for a slightly different prep method.
If you let gelatin come to a boil, it won't set well, so once the gelatin is added, don't let the pot come to a boil! If you prefer a wobbly texture, I recommend the agar version Recipe ID: 1526493 too.