I am new to cake decorating and just doing some courses now but I have a question about royal icing. I've made the wilton receipe and I don't like the taste of it and found the egg white with cream of tartar receipe. I used pasteurized egg whites from a carton so I am wondering if the royal icing is edible afterwards or are they non edible because of the egg whites and being left out to dry?

It's still edible... I make mine only with real egg whites.

Yes is edible.
Edna

It's edible. The egg whites from the carton are pasturized. You could drink them from the carton safely (if you wanted to). You can also purchase in the shell pasturized eggs.