Pam asks: I have a question that I am hoping you can help me with. I am making a lot of frosting for a gingerbread house project. It is royal frosting (egg whites, powdered sugar, and cream of tartar). Have you ever worked with this? Do you think I can make it the day before? Should I store in the refrigerator?
Baking S.O.S. says: Royal icing is tricky–I’m sure you’ve experienced it if you have made it before! It does not keep well. Once you mix it, you have to use it right away or it will harden and set to the point where you can no longer use it.
So unfortunately, you should make it as close to the time you intend to use it. The way to keep it from solidifying before you are ready to use it is: keep it in your mixing bowl (stainless steel usually works best), place a layer of plastic wrap directly on top of the frosting–being sure to get out any air bubbles, and then place a damp towel on top of the plastic wrap. That is the ONLY way I know to work with royal icing successfully!
Pam asks: Do you think it would work if I made it and then took it to school in zip lock bags that we could then just pipe it out of? Do you know of any other frosting that would work?
Baking S.O.S. says: Yes, I think it would work to put the Royal Icing in ziploc bags–being sure to squeeze out all the air before sealing them. (The exposure to air is what makes the frosting harden and set, and it cannot be revived after it has set.) When you are ready to use the icing, just snip a small corner off the bottom of the bag to squeeze it out. That is what I always do when I take frosting to school for kids to decorate cookies.
Royal Icing is really the only kind of frosting that you would want to use for gingerbread houses. Nothing else sets up as quickly or as steadfastly to “glue” everything together. Good luck! It sounds like a fun project to do at school with the kids.