Why Does Jello Jiggle?

Our food scientist Jared Levan has soloved the mysteries of brain freeze, the emotions caused by chopping raw onions and beans—the magical fruit. Today he takes on Jello-O's jiggle.

If there's one word that comes to mind when you think of Jell-O, it's most likely "jiggle." But while that characteristic wobble has made Jell-O a household name for gelatin across America, few people know the truth about why it does what it does.

What is Jell-O and why does it jiggle?

It's quite simple, really. Jell-O, also known simply as gelatin, is a substance formed when collagen — extracted from bone and other forms of connective tissue – are submerged in boiling water. As these proteins dissolve, the collagen bonds within are broken down, leaving tiny protein molecules and fragments. Hot water and collagen does not gelatin make, however. So what's missing? Actually, nothing is missing...the solution just needs time to cool down.

As long as the mixture is hot, the gelatin will remain a liquid. Put the bowl in a cold place like the refrigerator and that's a different story. The molecules of collagen have a tendency to aggregate and thicken when conditions are right, so as soon as the temperature has dropped enough, proteins will attempt to "come out" of the solution and bond to each other.

Through the process of hydrolysis – the chemical reaction by which water is added to a molecule or compound – the strength of these new bonds is weakened and much less rigid than in its natural state. As this occurs, water molecules become trapped between collagen molecules, much like trapping water inside a balloon; you'll notice the similarities in fluid motion of gelatin and a water balloon and that's no coincidence – that's just how water moves when confined to a given space. The only difference: no balloon – the gelatin has no need for a barrier to contain itself.

There's always time for a video, so go ahead...let these Jell-O videos mesmerize and distract you.