What is it exactly? It isn't really a solid but still not quite a liquid. Watch a video of Jello in slow motion! The main ingredient in Jello is gelatin. Gelatin is made from the principle protein collagen whis is found in animal skin bones and sinew. Have you ever made plain gelatin? It does not smell like anything you would actually want to ingest. Gelatin isn't just for Jello it has many other uses as well including: pharmaceuticals, photography, cosmetics and even to add the yellow color to soft drinks. Gelatin has been around since the time of ancient Greece but not as the tasty treat we know today. In ancient Greece it was used to bind, glaze and preserve foods.