How to Dirty ice or crumb coat a cake

Crumb coating, also known as dirty icing, a cake, does not, as its name suggests, mean adding crumbs to the outer coating of a cake. Instead, crumb coating is the step that most pastry chefs take to make sure that all the loose crumbs on a cake are trapped in an initial coat of icing so that when you add the second (and actual) icing layer no crumbs mix with the icing and look bad.

Check out this cake decorating tutorial to learn how to crumb coat a cake.