Homemade powdered sugar in a bowl with sugar, a blender, and a fine-mesh sieve

How to Make Icing Sugar at Home (Powdered Sugar Substitute)

3 minutes read

Ran out of powdered sugar halfway through a recipe? You can make a useful homemade alternative with ordinary granulated sugar and a powerful blender or spice grinder. This guide explains how to make icing sugar at home, when to add cornstarch, and why the homemade version may feel slightly different from store-bought confectioners’ sugar.

At a glance: About 5–10 minutes · No cooking · Makes roughly 1 cup · Use dry, high-powered equipment.

What is icing sugar?

Icing sugar, powdered sugar, and confectioners’ sugar are common names for finely milled white sugar. Some packaged varieties contain a little starch to resist clumping. The fine texture dissolves much faster in frostings and glazes than ordinary granulated sugar.

Ingredients and equipment

1 cup (about 200 g) white granulated sugar
1 tablespoon cornstarch (optional; helps prevent clumping)
High-powered blender, spice grinder, or dry food processor designed for milling
Fine-mesh sieve and dry, airtight storage container

How to make icing sugar at home

Step 1: Dry your equipment

Make sure the blender jar, blade, and lid are completely dry. Check your appliance instructions to confirm it can safely grind dry sugar. Never fill beyond the manufacturer’s recommended level.

Step 2: Add sugar and optional cornstarch

Pour the granulated sugar into your blender or grinder. Add cornstarch if you want a closer substitute for commercial powdered sugar and plan to store it.

Step 3: Grind to a fine powder

Pulse in short bursts, then blend until the sugar becomes soft and powdery. Depending on your machine, this can take roughly 1–3 minutes. Pause to prevent overheating and avoid inhaling airborne sugar dust.

Step 4: Let the dust settle

Turn the appliance off and keep the lid on briefly so that the fine powder settles before you open it.

Step 5: Sift

Sift through a fine-mesh sieve. Return any large crystals to the grinder and process again. The finest possible texture is important for a smooth icing.

Can you make icing sugar without cornstarch?

Yes. Pure ground sugar works particularly well for dusting cakes or quick glazes. With no starch, it may clump sooner in storage. If you use a homemade version in a delicate frosting, sift carefully and check the texture before making a full batch.

How homemade and store-bought powdered sugar differ

Factory-milled sugar is consistently very fine. A home blender may leave some grit, especially if it is not powerful enough. For precision baking such as French macarons, recipes that rely on ultra-fine purchased confectioners’ sugar are usually the more reliable choice.

What can you make with it?

Simple powdered sugar icing for cake or cookies
Dusting brownies, pancakes, and waffles
Glazes for cinnamon rolls and quick breads
Homemade buttercream (if your homemade powder is very fine)
Sweetening some whipped cream and no-bake fillings

Tips to avoid gritty powdered sugar

Grind small batches rather than packing the blender.
Use fully dry equipment; any water makes sugar clump.
Sift thoroughly and regrind visible crystals.
Let dust settle before opening the lid.
If the powder remains coarse, use purchased powdered sugar for silky buttercream.

How to store homemade icing sugar

Keep the powder in a tightly sealed, food-safe jar in a cool, dry cupboard, away from steam and moisture. Label the container if you added cornstarch. Inspect for moisture or unusual odors before use; because storage conditions vary, consider making small batches as needed rather than relying on a long shelf life.