How to Make Powdered Sugar at Home (2 Ingredients, 1 Minute)

In Short

To make powdered sugar, blend 1 cup of granulated sugar with 1 tablespoon of cornstarch for about 1 minute. It turns into a soft, fluffy powder. The cornstarch keeps it from clumping, so skip it if you'll use the sugar right away. Let the dust settle before you open the lid.

How to Make Powdered Sugar (Step by Step)

Powdered sugar is just granulated sugar ground into a fine powder.

Store-bought bags also have a little cornstarch mixed in. Domino adds it to keep the sugar from caking.

So yes, you can make it at home with two ingredients.

• Granulated sugar (1 cup). Regular white sugar or cane sugar.
• Cornstarch (1 tablespoon). Keeps it from clumping (optional).

1. Add the sugar and cornstarch. Use a clean, completely dry blender jar. Any water makes the sugar clump.
2. Lock the lid. Sugar dust gets everywhere, so drape a kitchen towel over the top too.
3. Blend on high. A high-speed blender needs about 1 minute. A regular blender may need a little longer.
4. Scrape once. Stop and scrape down the sides if sugar packs into the corners.
5. Check the texture. Rub a pinch between your fingers. It should feel silky, like flour, with no crunch.
6. Let it settle. Wait a minute or two before you open the lid.
7. Sift it. Push it through a fine-mesh sieve. Anything left behind goes back in for another spin.

That's it!

Small batches grind finer than big ones.

If you need 3 cups, blend 1 cup at a time instead of packing the jar.

Do You Need Cornstarch?

No, but it helps if you're storing it.

Cornstarch soaks up moisture, which is why it's in store-bought powdered sugar.

• Using it right away? Skip the cornstarch. Plain ground sugar works for a glaze or frosting you're making now.
• Storing it? Add 1 tablespoon per cup. Without starch, ground sugar clumps as it sits.
• Out of cornstarch? Use arrowroot or tapioca starch in the same amount.

For a quick glaze you'll pour right away, I recommend skipping it, since there's nothing to store.

Blender, Food Processor, or Coffee Grinder

Any of these will turn sugar into powder.

Some just do it faster and finer.

A spice grinder makes great powdered sugar.

Just clean it first, unless you want coffee-flavored frosting.

No appliance at all? A mortar and pestle works with patience. I'd save it for a little dusting sugar on brownies.

Measurements in Cups and Grams

Grinding fills the sugar with air, so the volume grows.

1 cup of granulated sugar makes about 1 3/4 cups of powdered sugar.

That lines up with King Arthur Baking's ingredient weight chart. It puts 1 cup of granulated sugar at 198 grams and 1 cup of unsifted confectioners' sugar at 113 grams.

The NDSU Extension substitution chart uses the same 1 cup to 1 3/4 cups swap.

Measure the powdered sugar after you blend it, not the granulated sugar going in.

A kitchen scale makes this easy. My baking measurement conversion chart has more cup-to-gram numbers.

Stacie's Tricks & Tips

• Sift for Frosting: Even a strong blender leaves a few bigger crystals. Sifting catches them, which matters most in a smooth cream cheese frosting.
• Don't Swap It Into Cakes: Powdered sugar isn't a cup-for-cup stand-in for granulated in cakes and cookies. Keep it for frostings, glazes, and dusting.
• Try Other Sugars: Cane sugar powders the same way. Coconut sugar turns into a tan powder with a caramel flavor.
• Skip Brown Sugar: It's too moist to grind well and gums up the blades.
• Store It Airtight: Keep it in a sealed jar in a cool, dry spot. Clemson Extension's pantry chart lists powdered sugar at 18 months.
• Use It Anywhere: Frosting, glazes, a dusting over brownies, or sweetening whipped cream without grainy bits. It's also what gives my wedding cookies their snowy double coat.
• Fix Clumps Fast: A quick pulse in the blender or a pass through the sieve breaks them up.

Key Takeaway

Keep a bag of granulated sugar and a box of cornstarch on hand, and you'll never stop a frosting halfway again.

Whip your fresh batch into my classic buttercream frosting, or go bold with this rainbow buttercream frosting.

Pipe away!