Does powdered sugar contain a small percent of cornstarch?

Yes, powdered sugar, also known as confectioner's sugar or icing sugar, often contains a small percentage of cornstarch. This is added as an anti-caking agent to prevent the sugar from clumping and becoming hard. The cornstarch helps to absorb any moisture in the sugar and keep the particles separated.

The amount of cornstarch added to powdered sugar can vary depending on the manufacturer. In the United States, the maximum amount of cornstarch allowed in powdered sugar is 5%. This is considered a food additive and is usually listed on the ingredient label.

In addition to preventing caking, cornstarch can also help to improve the texture of powdered sugar by making it smoother and easier to blend with other ingredients. It can also help to stabilize frostings and glazes by preventing them from becoming too runny.