Powdered Sugar
Granulated sugar ground to a fine dust and blended with starch to prevent clumping, ideal for smooth frostings.
1 Cup Powdered Sugar = 120g (4.25 oz) • 1 Cup Sifted = 110g
Powdered sugar (also known as confectioners' sugar or icing sugar) is granulated white sugar that has been mechanically pulverized into an ultra-fine, chalky dust. Because these microscopic sugar crystals are highly hygroscopic, they clump together instantly when exposed to any humidity. To prevent this, commercial powdered sugar is blended with 3% to 5% cornstarch or potato starch, which absorbs moisture and keeps the sugar free-flowing. The extremely small particle size allows powdered sugar to dissolve instantly without heating, making it the essential ingredient for smooth buttercreams, royal icings, glazes, and decorative dustings on pastries.
Because powdered sugar contains cornstarch, it cannot be substituted 1:1 for granulated sugar in baking batters. The starch will alter the flour-to-liquid ratio, and the lack of crystal structure will prevent air from being creamed into fats, resulting in dense, flat bakes. Sifting powdered sugar before use is highly recommended, as it removes any packed lumps that can clog piping tips.
Skipping sifting when making buttercream frosting. Pulverized sugar naturally packs into hard micro-lumps during shipping, which will remain as grainy spots in your finished frosting.
Known as Confectioners' Sugar in the US, Icing Sugar in the UK and Canada, and Pure Icing Sugar (no starch) vs Icing Sugar Mixture (with starch) in Australia.
Essential for uncooked frostings, glaze icings, royal icing, dusting over finished cakes, and making shortbread cookies.
1 cup powdered sugar = 1 cup granulated sugar ground in a high-speed blender for 60 seconds with 1 teaspoon cornstarch.
Keep in a tightly sealed container in a cool, dry place. It absorbs surrounding kitchen odors very easily.
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