What makes jello gel?

Gelatin. Gelatin is a protein derived from collagen, which is found in the skin, bones, and tendons of animals. When gelatin is mixed with water, it forms a gel because the collagen molecules absorb water and swell up, creating a network that traps water molecules. This network is what gives jello its characteristic jiggly texture.

The amount of gelatin used in a recipe will determine the firmness of the jello. More gelatin will result in a firmer jello, while less gelatin will produce a softer jello.

Other factors that can affect the texture of jello include the temperature of the water, the amount of sugar, and the type of mold used.