For The Best Royal Icing, Use Powdered Sugar With Tapioca Starch

Thick, glossy royal icing is not the recipe you reach for when you are looking for a delicious cake frosting. You probably only think of it as the sugary mortar that holds gingerbread houses together or the crunchy colorful layered on a decorated sugar cookie, and you'd be right in both cases. But that doesn't mean the icing shouldn't taste good, too. Most recipes include a few drops of extract to help mask the chalky flavor from one of the main ingredients: powdered sugar. That sweet powder includes about 3% cornstarch that helps prevent clumping and also extends shelf life, but doesn't taste great — and that's a problem because royal icing is mostly made of powdered sugar.

Luckily, powdered sugar with tapioca starch is available as a substitute, and although a little harder to find, it's worth the search for better-tasting royal icing. Tapioca starch prevents the finely ground sugar from clumping just like cornstarch does, but has qualities that eliminate the chalky taste and mouthfeel, making those frosted cookies a more enjoyable eating experience.

Tapioca comes from the root of the cassava plant. It's nearly flavorless, with a slight sweetness that enhances the overall icing. The starch granules in tapioca absorb water much easier than cornstarch, meaning they effortlessly disappear into royal icing, eliminating that chalky feel that is so disappointing on a cookie. Tapioca also creates a shiny finish in frosting compared to the matte finish that comes from cornstarch products. A better tasting, smoother, and shinier royal icing, all available just from switching up the starch in your powdered sugar.

You'll find most brands of powdered sugar with tapioca starch labeled organic or kosher due to its lack of corn products, which are often GMO and not also considered kosher for Passover. Corn is a major allergen, so tapioca containing powdered sugar is a great allergy-friendly product, too. The price is higher than standard powdered sugar, so we recommend using tapioca starch sugar for recipes when the powdered sugar is a major component, like royal icing. If you can't find a package of the sugar, you can also make your own in a blender, simply substituting tapioca starch for the cornstarch. A final note, because tapioca absorbs moisture so well, clumps in the powdered sugar are inevitable, but nothing a quick sift won't fix.