Gelatin is used as a stabilizer in many baking preparations. In small amounts, gelatin adds body, like to a sauce or whipped cream; in greater amounts, it can set a liquid so firmly that it can be sliced or cut into shapes. Using the precise amount of gelatin is crucial: If too little is used, it will not add enough stabilizing power, while if too much is used, the texture will become rubbery and unpalatable, and the flavor undesirable.
Gelatin is a protein composed of molecules that attract water; gelatin is hydrated, or bloomed, in order to allow these molecules to swell, absorbing moisture. Since the product will begin to set immediately after the gelatin is added, always prepare all molds, containers, and so forth before beginning preparation. Some gelatin-stabilized items are served in their molds; others are unmolded before serving.
- Gelatin must be rehydrated, or bloomed, and then melted before use. To bloom, soak it in the amount of liquid specified in the recipe, which should be approximately 1 cup (8 oz) of a water-based liquid for every 1 oz of granulated gelatin.
An alternate method, commonly used for blooming sheet gelatin, is to soak the sheets in enough ice cold water to completely submerge them. If this method is used, after blooming gently squeeze and wring the sheets to force the excess water out, so as not to add additional liquid to the formula, which would change the consistency and flavor of the finished product.
- After it is bloomed (hydrated), the gelatin must be melted. To melt bloomed gelatin, place it in a pan or bowl over low heat or a hot water bath until liquefied. Then stir the melted gelatin into a warm or room-temperature base mixture. (If the base is cold, the gelatin may set up prematurely.) If the base is quite warm or hot (at least 105°F/41°C), however, you may opt to add the bloomed gelatin directly to the hot base, rather than melting it separately, and allow the base’s heat to melt the gelatin. Be sure to stir gelatin added this way until it is completely blended into the base.
As the bloomed gelatin is heated, the water-attracting molecules dissolve completely. Through cooling, the proteins in the gelatin mixture join together to form a three-dimensional web that holds the absorbed moisture. It is the development of this system in the gelatin that results in what we know as a gel; when added to other mixtures, or bases, the presence of this protein web is what results in a set, stabilized product.
When working with gelatin, it is important to remember that there are a few fruits that contain proteases—enzymes that will break down the collagen in gelatin and not allow it to set (gel). Among these fruits are kiwi, pineapple, papaya, honeydew melon, and banana. To use these fruits in any gelatin-based application, you must first allow the fruit or fruit purée to simmer for 2 to 3 minutes to destroy all of the protease enzymes before adding the gelatin.
