is a good thickener to use with fruit to make a filling because it does not have any flavor and creates a smooth texture. It also does not thin when reheating a slice of pie. Cornstarch has twice the thickening power of flour, but doesn’t work well if the filling is high in acidity.
is often used because it can hold more fruit juices than other thickeners without becoming rigid. It is not recommended for a lattice top pie or other open fruit pie, as it hardens when exposed to the hot air of the oven. However, it can be used with a two-crust pie. Tapioca has no flavor and cooks quickly. If you use tapioca, let the filling mixture stand for at least 15 minutes before you spoon it into the crust to bake. This will allow for more efficient thickening. When you prepare a pie filling, mix the thickener first with sugar and any spices to prevent lumps and uneven thickening, then add the fruit. Granules are gritty if under cooked but are clear and soft when fully cooked.
is not a desirable choice because it thickens before the boiling point of fruit fillings in the pies. It imparts no flavor of its own but provides a high gloss, and just 1 tablespoon will firm up each cup of liquid. It’s fine for high- and low-acid fruit mixtures, but it creates a gloppy mess if mixed with any dairy product.
this gluten-free starch's main advantage over other starch thickeners is that it's a permitted ingredient for Passover, unlike cornstarch and other grain-based foods. Liquids thickened with potato starch should never be boiled.
― Yogi Berra