From Wikipedia: Arrowroot makes clear, shimmering fruit gels and prevents ice crystals from forming in homemade ice cream. It can also be used as a thickener for acidic foods, such as Asian sweet and sour sauce. It is used in cooking to produce a clear, thickened sauce, such as a fruit sauce. It will not make the sauce go cloudy, like cornstarch, flour or other starchy thickening agents would. The lack of gluten in arrowroot flour makes it useful as a replacement for wheat flour in some baking uses. Like other pure starches, however, arrowroot is almost pure carbohydrates and devoid of protein, thus it does not provide a complete substitute for wheat flour for bread-making, which requires gluten. Arrowroot thickens at a lower temperature than flour or cornstarch, is not weakened by acidic ingredients, has a more neutral taste, and is not affected by freezing. It doesn't mix well with dairy, forming a slimy mixture. It is recommended that arrowroot be mixed with a cool liquid before adding to a hot fluid. The mixture should be heated only until the mixture thickens and removed immediately to prevent the mixture from thinning. Overheating tends to break down arrowroot's thickening property. Two teaspoons of arrowroot can be substituted for one tablespoon of cornstarch, or one teaspoon of arrowroot for one tablespoon of wheat flour.