Best Substitutes for Confectioners' Sugar
Confectioners' sugar (also called powdered sugar or icing sugar) is granulated sugar ground to a fine powder with about 3% cornstarch added to prevent clumping. The ultra-fine texture dissolves instantly without grittiness, making it essential for smooth frostings, delicate cookies, and dusting. Regular granulated sugar has crystals about 0.5mm in size, while confectioners' sugar particles are roughly 0.1mm. That size difference matters. Frostings made with granulated sugar feel sandy. Meringues won't whip properly. When you substitute, you're fighting both texture and sweetness concentration (confectioners' sugar packs more sweetness per cup because the fine powder settles tighter than granulated crystals).
Best Overall Substitute
Make your own by blending 1 cup granulated sugar with 1 tablespoon cornstarch in a high-speed blender for 60-90 seconds until powder-fine. This creates the exact texture and anti-caking properties of store-bought confectioners' sugar at a 1:1 replacement ratio.
All Substitutes
Homemade powdered sugar
1:1Blend 1 cup granulated sugar with 1 tablespoon cornstarch in a high-speed blender or food processor for 60-90 seconds. The cornstarch (about 3% of the total weight) prevents clumping just like commercial versions. A Vitamix or Blendtec works best, but any powerful blender handles this. Let the powder settle for 2-3 minutes before opening to avoid a sugar cloud. Store in an airtight container for up to 6 months.
Granulated sugar (emergency only)
3/4 cup granulated sugar replaces 1 cup confectioners' sugarGranulated sugar dissolves in wet mixtures but creates texture issues in dry applications. Confectioners' sugar is about 25% more concentrated than granulated by volume, so reduce the amount. Works in buttercream if you beat it for 5-7 minutes instead of the usual 2-3 minutes. The crystals break down partially during extended mixing. Completely fails for dusting or dry applications where the grittiness shows.
Powdered erythritol
1 1/4 cups powdered erythritol replaces 1 cup confectioners' sugarErythritol is about 70% as sweet as sugar, so you need more volume to match sweetness. It has a slight cooling effect on the tongue that some people notice in simple frostings. Works identically to confectioners' sugar for texture because it's ground to the same fineness. Dissolves completely without grittiness. Some brands include anti-caking agents, others don't, so check the label. Swerve and Lakanto are reliable brands.
Powdered coconut sugar
1:1Coconut sugar ground to powder works exactly like confectioners' sugar for texture. The flavor is subtly caramel-like rather than pure sweet. Color ranges from light tan to deeper brown depending on the brand. Big Tree Farms and Terrasoul make good powdered versions. You can make your own by grinding coconut sugar in a spice grinder for 45-60 seconds, but it won't be as fine as commercial versions.
Powdered monk fruit sweetener
1/3 cup powdered monk fruit replaces 1 cup confectioners' sugarMonk fruit is 150-200 times sweeter than sugar, so a little goes far. Most powdered versions are blended with erythritol or other bulking agents to make measuring easier. Lakanto and Pure Monk are 1:1 sugar replacements by volume. Pure monk fruit powder requires much smaller amounts. Check your specific brand's conversion chart. No aftertaste when used in proper ratios.
Powdered stevia blend
1/3 cup stevia blend replaces 1 cup confectioners' sugarPure stevia is 200-300 times sweeter than sugar, but baking blends mix stevia with erythritol or other bulking agents. Truvia and Stevia in the Raw make powdered versions. Follow the package conversion ratios because they vary by brand. Some people detect a slight metallic aftertaste, especially in simple frostings where the stevia flavor isn't masked by other ingredients.
How to Adjust Your Recipe
When using granulated sugar as an emergency substitute, increase liquid slightly (add 1-2 tablespoons milk or cream per cup of sugar) to help dissolve the crystals. Beat frostings 2-3 minutes longer than usual. For dusting applications, there's no good substitute for the fine texture of confectioners' sugar. Alternative sweeteners may need flavor adjustments since they lack sugar's pure sweetness. Add 1/4 teaspoon vanilla extract per cup when using erythritol or monk fruit to mask any aftertaste. Royal icing made with sugar alternatives sets softer and takes 30-50% longer to dry completely.
When Not to Substitute
Royal icing decorating requires real confectioners' sugar because the cornstarch and fine texture create the specific consistency needed for clean lines and proper drying. Sugar work like pulled sugar or spun sugar can't use alternatives because you need sucrose's specific melting and crystallization properties. French macarons are extremely sensitive to ingredient ratios and won't work with substitutes. Fondant requires the exact texture and binding properties of confectioners' sugar mixed with glucose or corn syrup.
Frequently Asked Questions
How much cornstarch do I add when making homemade powdered sugar?
Add 1 tablespoon cornstarch per 1 cup granulated sugar (about 3% by weight). This matches the anti-caking agent ratio in commercial confectioners' sugar. More cornstarch makes the powder chalky. Less allows clumping. Arrowroot powder works as a 1:1 substitute for cornstarch if you need a corn-free version.
Can I use brown sugar to make powdered sugar?
Yes, but it clumps more than white sugar when ground. Use 1 cup brown sugar with 1 tablespoon cornstarch, blend for 90 seconds, then sift through a fine mesh strainer. The molasses content makes it slightly sticky, so it works better in moist applications like cream cheese frosting than for dusting.
Why does my homemade powdered sugar feel gritty compared to store-bought?
Your blender isn't powerful enough or you didn't blend long enough. High-speed blenders (Vitamix, Blendtec) create powder that matches commercial texture after 60-90 seconds. Regular blenders need 2-3 minutes and still won't get as fine. Food processors work but require pulsing in 30-second intervals to prevent overheating.
How long does homemade powdered sugar last?
Store in an airtight container for up to 6 months at room temperature. It won't spoil, but it absorbs moisture and odors over time. If it clumps, sift it before using. The cornstarch helps prevent clumping for about 3-4 months, then humidity starts winning the battle.
Can I substitute confectioners' sugar for granulated sugar in cookies?
Not at a 1:1 ratio. Use 1 3/4 cups confectioners' sugar to replace 1 cup granulated sugar because it's more concentrated. Cookies spread less and have a more tender, melt-in-your-mouth texture. The cornstarch acts as a tenderizer. Works best in shortbread, sugar cookies, and other tender cookies rather than chewy varieties.