Baking

Powdered Sugar

Powdered sugar's hub page centers on the gap between its 120g-per-cup weight and granulated sugar's 200g — the same base ingredient at five-eighths the density, since it's pulverized into a fine powder and blended with about 3% cornstarch to prevent caking.

That cornstarch content is the single fact worth carrying across this whole page: it means powdered sugar isn't a pure sweetener, which matters if a recipe is sensitive to starch content, though for its overwhelming majority use — icings, glazes, dusting — the small percentage is essentially unnoticeable.

Powdered sugar doesn't have a dedicated storage or substitutes page on this site, since it's shelf-stable indefinitely like granulated sugar and its cornstarch content means a straight granulated-sugar swap changes a recipe's structure, not just its sweetness — worth converting through this site's Ingredient Converter tool rather than assuming a simple 1:1 works.

Powdered sugar's fine texture and small added amount of cornstarch (roughly 3%, included to prevent clumping) are both essential to its role in glazes and frostings — the cornstarch also means powdered sugar isn't a clean substitute for granulated sugar in recipes relying on sugar's crystalline structure, like meringues, since the added starch changes both dissolving behavior and finished texture.

Sifting powdered sugar before use breaks up clumps that reliably form during storage, giving a considerably smoother finished glaze or frosting than unsifted sugar would — a small extra step that makes a real visible difference in the final texture.

A basic glaze is often nothing more than powdered sugar whisked with a small amount of milk or water until pourable, with the ratio adjusted by eye until it drips slowly off a spoon rather than running thin — one of the simplest and most versatile uses for powdered sugar in home baking.

Powdered sugar became commercially practical only once industrial milling technology could reliably grind sugar to such a fine consistency — in earlier eras, achieving a similarly fine sugar for glazes and confections required considerably more manual labor than modern manufacturing needs.

Royal icing, made from powdered sugar and egg whites (or meringue powder), hardens to a considerably firmer, more brittle finish than a simple milk-based glaze — a distinct application relying on powdered sugar's fine texture combined with a different binding agent.

Snow sugar, a specially formulated non-melting powdered sugar used for dusting desserts that will sit for a while before serving, resists absorbing moisture in a way standard powdered sugar doesn't.

Fondant, used to create a smooth, moldable cake covering, is essentially a highly worked mixture of powdered sugar and corn syrup, a specialized application distinct from a simple glaze.