Additional Ingredients

Appears in
On Food and Cooking

By Harold McGee

Published 2004

  • About
Other common ingredients have various effects on gel strength when included in a jelly.

How gelatin turns a liquid into a solid. When the gelatin solution is hot (left), the water and protein molecules are in constant, forceful movement. As the solution cools and the molecules move more gently, the proteins naturally begin to form little regions of collagen-like helical association (right). These “junctions” gradually form a continuous meshwork of gelatin molecules that traps the liquid in its interstices, preventing any noticeable flow. The solution has become a solid gel.