Cornstarch is a thickening agent used in gravy, sauces and fruit desserts. When heated, the cornstarch binds with the liquid or fruit juices and becomes transparent, glossy and thick. Tapioca, derived from the root of the cassava plant, comes in two forms. Pearl tapioca consists of tiny pearls, or balls, of tapioca. Instant tapioca has smaller balls than pearl tapioca. Bleached wheat flour is a substitute for cornstarch and both types of tapioca.
Sauce & Gravy
Double the amount of cornstarch that the gravy or sauce recipe calls for and use that doubled amount of flour. For example, if the recipe calls for 1/2 cup of cornstarch, use 1 cup of flour. Put the flour in a jar with a lid. Add 1/2 cup of the liquid that the recipe calls for. The liquid should be room-temperature or colder -- not hot.
Put the lid on the jar. Shake well for 30 seconds. Open the lid and scrape around the bottom of the jar with a butter knife or spatula to make sure that all of the flour has been incorporated into the liquid. Replace the lid and shake again.
Pour the flour mixture through a strainer into the rest of the ingredients. Stir well. Bring the ingredients to a boil over medium heat, stirring constantly. Lower the heat to medium and simmer for two minutes.
Double the amount of cornstarch that the dessert filling recipe calls for and use that doubled amount of flour. Sprinkle half of the flour over the fruit.
Toss well. Scoop the fruit from the bottom of the bowl up and over the fruit on the top of the bowl so each piece gets coated with some flour.
Sprinkle the other half of the flour over the fruit and toss again. Proceed as the recipe directs.
Measure one and one-half (1.5) times the amount of instant tapioca that the recipe calls for and use that amount of flour. If the recipe calls for pearl tapioca, use an equal amount of flour.
Combine the flour with 1/4 to 1/2 cup of cold water. Blend well.
Add the flour mixture to the dish two minutes before it has finished cooking. While tapioca can be added at the last minute, since it won't impart a starchy taste, flour needs to be cooked or else it will taste raw.