Meringue powder is one of the main ingredients used in icings and frostings. A fine, white powder, it is made of dried egg whites, sugar, gum and salt, according to JoyofBaking.com. Adding meringue powder to a butter-cream frosting works as a stabilizer, making it easier to work with to make flowers, leaves or other frosting decorations.
Measure 3 cups of butter-cream frosting and put in a mixing bowl. Add 1 tbsp. of meringue powder.
Mix with an electric mixer at a slow speed for one minute. Turn off mixer.
Scrape sides of mixer bowl with spatula, then mix again with electric mixer for another minute on medium speed.
Put 1/4 tsp. of frosting between fingers and roll into a ball. According to "Diary of a Cake Stylist," if you can roll frosting into a ball and no frosting residue is left on your fingers, the frosting is too stiff and it will end up cracking. Add 1/4 tsp. of water to the frosting mixture and mix by hand. Repeat with more water if necessary.