This common icing is used primarily for decoration since it holds up well over time. It technically is edible but it is not very tasty to eat, especially if it has a lot of food coloring in it. It dries to the touch in just a couple of hours, and over time becomes very hard. It is perfect for sugar skulls because you can color it brightly, it lasts for years and you can even use it as a "glue" to add feathers and other decorations. You should be able to find most of the ingredients at your grocery store, but you may need to find a cake supply store for the paste food coloring and meringue powder. These are also easily ordered online from a variety of suppliers. I prefer to use this Meringue Powder and these Paste Food Colors (found near the bottom of the page there) but you can use which brand you like.
- 2/3 cup water
- 1/2 cup meringue powder
- 2 lbs powdered sugar
- 2 drops Paste food coloring in a variety of colors
You will also need:
- An electric stand mixer
- covered container
- disposable cups
- wooden popsicle sticks (optional to use in place of a spoon for mixing the colors)
- pastry bags (one for each color)
- decorating tips (optional)
Add all of the ingredients into a mixing bowl and mix on high for a minute or two, then scrape the sides of the bowl down to make sure everything is mixed in. Beat on high for another 7 to 8 minutes. Once the icing is mixed, pour it into a container and put the lid on to keep it moist. Because it has no fat in it, Royal Icing will dry out fast.
Get out as many disposable cups as you need for each color. We usually use 6 to 8 colors, but you may need more or less than that. Divide the icing into the cups evenly. Use a wooden stick or another utensil to scoop out some of the paste food colorings and stir it into the icing. A pea-size dollop will work for a lighter tone and you may need three or four pea-size amounts for an intense hue. Thoroughly mix the icing until no streaks are left. As soon as it is properly mixed, spoon or scrape it into a pastry bag. This is best done with two people so that one can hold the bag, and one can get the icing in. Hold the bag point-down and wrap the upper portion of the bag down around your hand. Then spoon the icing in, and pull the top of the bag off of your hand. That will keep the icing on the bottom near the tip. Twist the top of the bag where the icing stops, to keep the air out.
Repeat that same process for each different color of icing. If you are going to have more than three people decorating, you may want to double up the colors and have two of each.
When you are ready to use the icing, snip the tip off the pastry bag and squeeze the icing onto the sugar skull slowly with the tip facing directly at the skull. Place additional decorations into the freshly applied icing. The outside shell of the icing will dry in about 30 minutes to an hour. But you will need to allow up to 24 hours for it to dry solid.