Tapioca Improves the Texture and Moisture in Baked Goods
One of the first alternative flours bakers turn to is tapioca, which is valued in gluten-free baking for the texture and moisture it lends a baked good, and in other cooking as a thickening agent.
Tapioca is the starch extracted from the cassava root (aka yuca or manioc), native to South America. While the plant is easy to cultivate, care must be taken to ensure the roots are not harmed by insects while they grow. The roots are equally delicate when harvested; if they are damaged when the plant is dug up, they produce coumaric acid, which discolors them.
The roots have to be processed immediately, first to remove their naturally occurring cyanide (tapioca flour contains only trace levels of cyanide and is safe to consume). The starchy liquid that is left after processing the root dries up to become tapioca flour, which is different from cassava flour, which is made from drying and grinding the whole root.
It’s used most often as a thickening agent—remember tapioca pudding?—and is essentially flavorless and translucent, making it an ideal thickener for a variety of dishes.
Tapioca is available in pearls ranging from one to eight millimeters in size (the larger pearls used for boba tea), as well as flakes, sticks, and powders.
You can substitute tapioca flour for all-purpose in many recipes, especially quick breads and cakes, although it’s often better to blend it with nut, coconut, or rice flour to prevent the baked goods from becoming gummy. Keep in mind that tapioca flour and wheat flour differ in weight, so the volume will vary.