A common question we are asked is how to make black icing that really looks black and not gray. It can be challenging because adding too much icing color can impact the taste. Here’s what I tell my students:
You will achieve a true, deep rich black color which is so popular for wedding cakes today, such as details for stringwork or embroidery work. For example, the Black Tie Affair Cake is topped with black buttercream cornelli lace.
If you have added too much black color in the beginning and your buttercream seems to have somewhat of a bitter taste, I suggest adding either 2 tablespoons of cocoa or a flavoring such as cherry or orange, about 1 teaspoon, to 2 cups of icing.
Black coloring will not stain a glass or stainless bowl. It is possible it will stain a plastic bowl.