Powdered sugar is used primarily for frostings, glazes, icings, and dusting desserts, but it also plays a key role in specific baked goods where a smooth, tender texture matters. Its ultra-fine particles dissolve almost instantly, making it the go-to sweetener anytime you need sugar to disappear into a mixture without any graininess.
What Powdered Sugar Actually Is
Powdered sugar is just regular granulated sugar ground into a very fine powder. Commercial versions contain between 2% and 5% of an anti-caking agent, usually cornstarch, to absorb moisture and prevent clumping. That small amount of starch is worth knowing about because it slightly thickens anything you mix the sugar into, which is actually part of why frostings made with powdered sugar hold their shape so well.
You’ll see it labeled as confectioners’ sugar or icing sugar depending on where you live. The most common grade sold in grocery stores is 10X, meaning it’s been processed to be extremely fine. Lower grades like 6X and 4X have coarser particles and are mostly used in commercial food production. For home baking, 10X is almost certainly what you have in your pantry.
Frostings, Glazes, and Icings
This is the most common use for powdered sugar. Because it dissolves so quickly into butter and liquid, it creates silky smooth frostings without any gritty texture. A standard American buttercream is essentially just powdered sugar beaten into butter with a splash of milk or cream. Granulated sugar can’t do this job because the crystals won’t fully break down, leaving a sandy mouthfeel.
For glazes, you only need powdered sugar and a small amount of liquid. Mix it with milk, water, or citrus juice and you get the glossy, pourable coating you see on donuts, scones, and cinnamon rolls. Adjusting the ratio of sugar to liquid lets you control the thickness, from a thin drizzle to a thick, opaque coating.
Royal icing, the stiff white icing used for intricate cookie decorating, also depends on powdered sugar. It’s made by combining the sugar with egg whites or meringue powder, and the fine particle size is what allows the icing to pipe cleanly through tiny tips and dry to a hard, smooth finish. Fondant, the smooth rolled covering used on wedding cakes and specialty designs, relies on powdered sugar as well to achieve a pliable, clay-like consistency.
Dusting and Decoration
A light sift of powdered sugar over brownies, pancakes, French toast, or pastries adds sweetness and a polished look with almost no effort. The fine powder clings to surfaces in a way granulated sugar can’t, creating that classic snowy appearance on lemon bars or beignets. You can also use stencils to create patterns on cakes by laying the stencil flat and sifting powdered sugar over the top.
One thing to keep in mind: powdered sugar absorbs moisture from the air and from the food it sits on. If you dust something hours before serving, the sugar can dissolve and turn translucent. For best results, dust right before bringing the dessert to the table.
How It Changes Baked Goods
Powdered sugar doesn’t behave the same as granulated sugar in baked goods, and the difference matters. In a standard cake recipe, granulated sugar crystals cut into butter during creaming, creating tiny air pockets that help the cake rise and develop a light crumb. Powdered sugar dissolves too quickly to do this. A cake made entirely with powdered sugar tends to come out denser and drier, with a texture closer to a scone.
But that same property is exactly what makes powdered sugar ideal for shortbread and other dense, buttery cookies. Because it doesn’t incorporate air, it produces a supremely tender, melt-in-your-mouth texture. Mexican wedding cookies, Russian tea cakes, and classic shortbread all use powdered sugar for this reason. The cookies hold together with a delicate, crumbly bite instead of a chewy one.
Powdered sugar also produces less browning than granulated sugar. The Maillard reaction, the chemical process that gives baked goods their golden color, happens less evenly with the finer particles. So if you want a pale, delicate-looking cookie, powdered sugar helps. If you want deep caramelization, stick with granulated.
Candy and Confections
Many candy recipes call for powdered sugar because it blends into mixtures without needing heat to dissolve. Peppermint patties, truffles, cream cheese mints, and no-bake fudge recipes frequently use it as the base sweetener. It also shows up in homemade marshmallows, where a coating of powdered sugar (mixed with cornstarch) keeps the sticky surfaces from fusing together.
Whipped Cream and Meringues
Powdered sugar is a popular choice for sweetening whipped cream because it dissolves instantly into the cold cream without leaving any crunch. The cornstarch in commercial powdered sugar also acts as a mild stabilizer, helping the whipped cream hold its shape slightly longer than cream sweetened with granulated sugar. For meringues, some bakers use a blend of granulated and powdered sugar to get both the structural benefits of crystals and the smooth dissolution of the powder.
Calories and Nutritional Differences
Powdered sugar and granulated sugar have the same calorie content per gram since they’re the same substance, just different particle sizes. A tablespoon of granulated sugar contains about 49 calories and 12 to 13 grams of carbohydrates. A tablespoon of powdered sugar contains fewer calories only because the fluffy powder packs less densely into a measuring spoon. By weight, they’re identical. Neither contains any meaningful vitamins, minerals, or other nutrients.
Making It at Home
If you run out, you can make powdered sugar in about 60 seconds. Combine one cup of granulated sugar with one tablespoon of cornstarch in a blender or food processor and blend until the mixture is fine and fluffy. Keep the lid pressed down firmly, as the powder will try to escape. Homemade powdered sugar works well for frostings and dusting, though it may not be quite as uniformly fine as the commercial version. Store any extra in an airtight container to keep moisture out.