Royal icing is a fickle beast, and there is no way to give a precise recipe for it. The variables of humidity, heat, coloring, all make a difference in the final product. So consider this recipe a base that will need your fine tuning depending on your environment.
2 pounds powdered sugar
5 tablespoons meringue powder
3 teaspoons extract or emulsion
1/2-3/4 cups warm water
Set aside 1/4 cup of the water and stir in the flavoring. Using a paddle attachment, mix the sugar and meringue powder on the lowest possible setting. Keeping your mixer on its low/stir setting, slowly add the water/flavoring mix to the sugar and meringue. During this step, the icing will get thick and clumpy. Continue to add the remaining water until the icing reaches a honey-like consistency. Once you get to that ‘honey’ point, turn your mixer to medium speed and mix for two-four minutes. Your icing will get thick and start to develop some peaks. Your mixing time will most likely vary dependent on your temperature and humidity, so make sure you keep watch. Once your icing is forming soft peaks, stop.
There are some things to keep in mind here.
- After you have mixed up your icing, place a damp towel over the mixing bowl while you divvy out your icing to make your colors. This prevents your icing from drying out and making chunks.
- I only start with about 1/2 – 3/4 cup of the icing to mix my color in first. This seems to be a safe amount for pastry bags and icing bottles alike.
- I always mix my color in first before I thin my icing. This gives you a better chance of your coloring not making your icing too thin.
- After I have reached my desired color, I do the 12 second test. Take a clean metal spatula and run it blade side through, from one side of the measuring cup. The goal is to get the icing to close the cut in 12 seconds. If it takes longer, add water by the 1/4 teaspoon. If it takes less, add sugar by the 1/2 teaspoon until the thickness is reached. 12 seconds works very well for me as a loose piping but not quite flood. For flood, I take it to about 8-10 seconds.
- After I have reached the desired color and consistency, I put my icing in a bag or bottle and seal it with a tip cap or plastic wrap to keep the air out until I am ready to use it.