Solid Dispersions: Jellies

When the water phase of a food fluid has enough thickening molecules dissolved in it, and the fluid is left undisturbed and allowed to cool, those molecules can bond to each other and form a loose but continuous tangle or network that permeates the fluid, with the water immobilized in pockets between the network molecules. Such a network thickens the fluid to the point that it becomes a very moist solid, or a gel. It’s possible to make a solid—if wobbly—jelly that is 99% water and just 1% gelatin. If the gel is made from dissolved molecules, then it will be translucent, like the dispersion from which it is formed. Familiar examples are savory jellies made from gelatin and sweet jellies made from fruit pectin. If the solution also contains particles—the remains of starch granules, for example—then the jelly will be opaque.