Best Powdered Sugar Substitutes (With Ratios)
The best powdered sugar substitute is homemade: blend 1 cup (200 g) granulated sugar with 1 Tbsp (8 g) cornstarch in a blender for 1–2 minutes until fluffy and fine. That makes about 1 3/4 cups, enough to replace the same volume of icing sugar in frosting, glaze and dusting.
Powdered sugar substitutes and ratios
| Substitute | Amount per 1 cup (120 g) powdered sugar | Best for | Why it works |
|---|---|---|---|
| Blended granulated sugar + cornstarch | Scant 2/3 cup sugar + 1 1/2 tsp cornstarch, blended | Frosting, glaze, dusting | Same sucrose ground fine, with anti-caking starch |
| Blended granulated sugar, no starch | Scant 2/3 cup sugar, blended | Whipped cream, use immediately | Fine crystals dissolve fast; clumps if stored |
| Blended sugar + arrowroot or tapioca | Same as cornstarch version | Corn-free baking | Any fine starch prevents caking |
| Blended coconut sugar + cornstarch | Scant 2/3 cup + 1 1/2 tsp starch | Rustic glazes, spiced bakes | Works the same; tan colour and caramel taste |
| Caster (superfine) sugar | 2/3 cup | Meringues, whipped cream | Dissolves quickly; not fine enough for smooth icing |
| Powdered erythritol or allulose | As per package | Low-sugar frosting | Ground fine; erythritol can recrystallize |
| Dry milk powder, blended with sugar | 1/2 cup sugar + 1/4 cup milk powder | Dusting, sweet coatings | Fine, sweet and creamy; less sweet |
Why fine sugar matters
Powdered sugar is ordinary sucrose milled so fine that individual particles are tiny. That surface area changes how it behaves:
- Instant dissolving. In a little milk or lemon juice, fine particles dissolve almost immediately, giving a smooth glaze. Granulated crystals dissolve slowly in small amounts of liquid, so icing made with them stays gritty.
- Smooth texture without heat. Buttercream and cream cheese frosting contain very little free water, so sugar must already be tiny to feel smooth on the tongue.
- Drying and setting. The roughly 3% cornstarch absorbs moisture, keeps the powder flowing and helps glazes set firm.
Because powdered sugar is fluffy, a cup weighs about 120 g, while a cup of granulated weighs about 200 g. That's why 1 cup granulated turns into roughly 1 3/4 cups powdered. Measure by weight when you can.
When not to swap
- Shortbread and some cookies. Recipes built on powdered sugar rely on its fine texture and starch for a sandy, tender crumb. Granulated makes them crisper and more spread out.
- Granulated sugar in no-cook frostings. Always grind it first.
- Erythritol in frosting you'll store. It can recrystallize into a crunchy, cooling texture overnight.
- Recipes that weigh powdered sugar. Swap by weight, not volume, or the bake will be far too sweet.
Questions
Can I make powdered sugar without a blender?
A clean coffee or spice grinder works best for small batches. A food processor can work but often leaves it slightly gritty, so sift it after grinding.
Do I need cornstarch in homemade powdered sugar?
Not if you use it right away. Cornstarch stops it clumping in storage and helps icing set. Skip it, or use arrowroot or tapioca starch, if you prefer.
Can I use granulated sugar instead of powdered sugar in frosting?
Not without grinding it. The crystals won't dissolve in butter or cream cheese, so the frosting stays gritty. Blend the sugar fine first.
Are powdered sugar, icing sugar and confectioners' sugar the same?
Yes. They're all very finely ground sucrose, usually with about 3% cornstarch added as an anti-caking agent.