Icing Sugar vs. Powdered Sugar: What’s the Real Difference?
Icing sugar and powdered sugar are the same fine, white sweetener made by grinding granulated sugar into a silky powder and adding a touch of cornstarch to prevent clumping. The only real difference is the name: “icing sugar” in the UK and most Commonwealth countries, “powdered sugar” in the US and Canada.
Recipes swap the terms without warning, so British bakers search for icing sugar while Americans reach for powdered sugar. Because packaging never clarifies that both dissolve instantly and sweeten identically, pantry panic sets in when only one label is visible.
Key Differences
Texture and additives are identical; the divergence is purely linguistic. UK brands label it “icing sugar,” US brands “powdered sugar,” and both may offer 10X fineness. Cornstarch content hovers around 3 %, regardless of name.
Which One Should You Choose?
Choose whichever your local store stocks. If you’re reading a British recipe in the States, grab powdered sugar. Conversely, American bakers in the UK should buy icing sugar. Results remain flawless.
Examples and Daily Life
Sprinkle over beignets in New Orleans or dust atop Victoria sponge in London—same snowy finish. Holiday cookies and quick glazes work interchangeably, so don’t overthink the label.
Can I substitute caster sugar for icing sugar?
No; caster sugar is coarser and won’t dissolve smoothly, leaving frostings grainy.
Why does my powdered sugar taste slightly starchy?
The added cornstarch prevents caking; it’s normal and undetectable once mixed into icing.
Is 10X sugar different from 4X?
10X is simply finer, ideal for smooth glazes; 4X feels slightly gritty and is less common today.