I just received an e-mail asking me about using tapioca starch to thicken soups and desserts. Tapioca, manioc, or cassava starch is a fine white powder produced from the cassava root, which is grown in Central and South America, Florida, the Caribbean Islands, and temperate climates around the world. While sweet cassava roots can be used as you would a sweet potato, tapioca products are usually produced from bitter cassava through a process of fermentation and draining or washing and pressing, then drying. The starch looks and is used much like cornstarch but, as a thickener, produces a much clearer and slightly more fragile sauce. Tapioca flour, instant tapioca, granulated, and pearl tapioca are also made from the cassava root by modifying the last steps in production. Instant tapioca and tapioca starch are the best choices for thickening. To substitute for wheat flour in a sauce or pie recipe use 1 tablespoon instant tapioca or 1 1/2 teaspoons tapioca starch for each tablespoon wheat flour in the original recipe. Tapioca starch has received much attention recently as a gluten-free replacement for wheat flour in baked goods and an ingredient in the Brazilian bread, Pão de Queijo. To make shopping more confusing, when hunting for tapioca, manioc, or cassava starch in natural foods or markets specializing in South and Central American products, you are likely to find more tapioca, manioc, or cassava flour than starch. Depending on the producer this can be a more coarsely ground product or the pure starch. Be sure to read the package for clues. If you purchase the more coarsely ground flour, you may need to increase the amount you use for thickening.