Cooling Temperatures

The temperature at which the gel forms and ages affects its texture. When “snap-chilled” in the refrigerator, the gelatin molecules are immobilized in place and bond to each other quickly and randomly, so the bonds and the structure of the network are relatively weak. When allowed to set slowly at room temperature, the gelatin molecules have time to move around and form more regular helix junctions, so once it forms, the network is more firm and stable. In practice, jellies should be set in the refrigerator to minimize the growth of bacteria. Gelatin bonds continue to form slowly in the solid jelly, so snap-chilled jellies become as firm as slow-chilled jellies after a few days.