Royal icing is hands down my favorite icing for cookie decorating. The egg whites in royal icing make it faster drying than confectioner’s icing, where the liquid content is usually milk or cream, and better for fine detail work, as it’s less prone to spreading. Use this thick formulation as edible glue for adhering sugar dragées and fondant appliqués to cookie tops, or for piecing together 3-D structures. For outlining, flooding (aka topcoating), marbling, and other cookie decorating techniques, just thin with water per my consistency adjustments until the desired consistency is reached.

Quick Flooding (Topcoating) Technique with Royal Icing | Photo by Steve Adams

About 4 1/2 cups (2 1/4 lb/1.0 kg), enough to topcoat/flood 4 to 5 dozen (3-in/7.6-cm) cookies

Prep Talk
  • It’s extremely important to use a very fine powdered sugar (i.e., 10X, which is commonly found in grocery stores in the United States, but sometimes harder to find in other countries). The sugar should not be at all gritty, or it will plug pastry tips when doing fine piping work. 
  • As always, it’s best to weigh all ingredients for most accuracy and consistency, and to add the egg whites gradually. The icing should be very stiff coming off the mixer, at what I refer to as my “glue” consistency.
  • To guard against salmonella poisoning associated with some raw eggs, it’s best to use pasteurized whites (or hydrated meringue or albumen powder) especially when serving the very young or old, or those with compromised immune systems. Pasteurized whites are found in cartons, or pasteurized in the shell, in the refrigerated section of most grocery stores. If using pasteurized eggs in the shell, you may find the eggs harder to separate than normal, so you may need to use an additional egg white. If using meringue powder, it’s best to follow the package instructions for reconstituting an egg white. In the absence of them, use 2 teaspoons meringue powder hydrated in 2 tablespoons warm water for each large egg white called for in this recipe. Be sure to hydrate with warm water to completely dissolve the powder; otherwise, your icing may end up gritty.
  • 2 pounds (907 g) powdered sugar
  • 1/2 teaspoon (2 g) cream of tartar
  • 5 large egg whites (5.0 oz/142 g)
  • Flavoring, to taste
  • Liqua-gel food coloring of your choice, to desired shade

1 | Mix the powdered sugar and cream of tartar together in the bowl of an electric mixer. Stir in the egg whites by hand to moisten the sugar. Fit the electric mixer with a paddle attachment, and beat the mixture on low speed to evenly distribute the egg whites. Turn the mixer to high speed, and continue to beat about 1 to 2 minutes just until the icing is silky and very white. (The icing will lighten and thicken as you beat it.)

Take care not to beat the icing any longer than is needed to turn it crisp white, and to only beat it at high speed at this very thick consistency. Extended beating, especially of looser icing, can pump a lot of air into it, creating tiny (or not so tiny) bubbles that can be difficult to eradicate once incorporated.

The icing, at this point, should be quite thick, at what I call my “glue” consistency. It should be so thick that it clings, nearly indefinitely, to a spoon, or plops off with a few aggressive shakes. (For a visual guide, see photo 1 in the gallery below.)

2 | Beat in flavoring and/or coloring, as desired. Again, take care not to overbeat for the reasons noted in Step 1.

Consistency Adjustments

The following consistency adjustments are approximate guidelines for 1 cup (11 oz/312 g) of thick, un-tinted royal icing, aka “glue”, as mixed per the recipe above. The addition of food coloring or flavoring, beating time, and normal variations in egg size can all affect the end-consistency of your icing.

If after making these adjustments, you think your icing is too thin or too thick for your application, don’t worry. The icing consistency can be adjusted at any stage of the decorating process simply by stirring in sifted powdered sugar to thicken, or water to thin. Remember, at this stage, it is important to gently stir in (not whip on the mixer) any additional water. As the icing loosens, you’re much more likely to kick air bubbles into it even with modest stirring.

For putty: “Putty” is a term I coined to convey super thick royal icing that can be shaped and modeled, much like fondant (though putty is less flexible). To make royal icing putty, simply add enough powdered sugar to my thick royal icing “glue” until it becomes a thick paste that doesn’t stick to your hands (or only sticks minimally).

For roses: I prefer a very thick icing, thicker than the “glue” consistency coming off the mixer, but a fair bit thinner than “putty”. It should take some work to stir the icing at this consistency.

For outlining aka piping: Add 1/2 to 3/4 teaspoon water to 1 cup icing “glue”. For crisp, well-defined outlines, start with 1/2 teaspoon water. If the icing is too thick to easily pipe through a small (1/8-in/3-mm or less) hole in a parchment cone, gradually add more water. When piped, the icing should hold a thin line with no – or minimal – spreading (photo 2).

For stenciling: Generally, 1/2 to 1 teaspoon water (per 1 cup icing “glue”) works best, though the exact quantity will vary with the size of stencil openings, the distance between stencil openings, the degree of stencil coverage, and other factors. The icing must be thin enough to easily spread into the stencil openings without leaving tracks or peaks when the spatula or stencil is lifted. At the same time, it must be sufficiently thick to keep from creeping under the stencil into areas where it is not wanted. It is better to err on the thicker side, especially with very fine and closely spaced stencil openings.

For marbling aka pull-through work: A consistency thicker than flooding consistency (i.e., about 3/4 to 1 1/2 teaspoons water per cup of icing “glue”) usually works best, as long as all of the icings you’re using still marble fluidly without the appearance of “tracks.” The smoothest, sharpest marbling effect is also achieved when all icings are as close to the same consistency as possible.

For flooding aka topcoating: To avoid icing run-off on cookies under 2 in/5.1 cm, start by adding 1 1/2 teaspoons water to 1 cup icing “glue”. Gradually increase to 2 to 2 1/2 teaspoons, as needed, to improve spread-ability on larger cookies. The icing should flow gradually off a spoon (photo 3) when at the proper consistency.

For dipping: Generally, an additional 1 1/2 to 2 teaspoons water (per 1 cup icing “glue”) works well, with the larger quantity needed on larger (greater than 2- to 3-inch/5.1-cm to 7.6-cm) pieces to ensure smooth coverage. When at the proper consistency, the icing should run gradually off the dipped piece and coat it relatively thickly (so you can’t see through it) without being so thick as to leave tracks.

For beadwork: About 2 to 3 teaspoons water (per 1 cup icing “glue”) works best, though, again, the exact quantity will vary. At the proper consistency, the icing will flow steadily off a spoon (photo 4), and a smooth, well-rounded dot will form when the icing is piped through a small (1/8-in/3-mm or less) opening in a parchment pastry cone (photo 5). If the icing forms a peak, it is too thick. Conversely, if it spreads a great deal, it is too loose.

Again, for a visual guide to proper consistency, see the photos in the gallery below or check out the following video (one of my very first YouTube tutorials), which goes into the above recipe and consistency adjustments in greater detail:

Lastly, for an explanation of the outlining and flooding techniques also shown in the gallery (photos 6 and 7), look no further than this YouTube video: