Royal icing is safe to eat, but with one important caveat: traditional recipes use raw egg whites, which carry a small risk of Salmonella contamination. The fix is simple. Swap in pasteurized egg whites or meringue powder, and that risk disappears entirely.
The Raw Egg Question
Traditional royal icing is just three ingredients: raw egg whites, powdered sugar, and a splash of lemon juice or cream of tartar. The egg whites give it that smooth, glossy finish that dries hard, which is why it’s the go-to for cookie decorating and gingerbread houses. But raw egg whites are the one ingredient that raises a food safety flag.
Salmonella bacteria can be present inside an egg before the shell even forms, meaning you can’t wash or inspect your way to safety. Most people who contract Salmonella develop diarrhea, fever, vomiting, and stomach cramps within six hours to six days, with symptoms lasting four to seven days. In rare cases, the infection spreads to the bloodstream and becomes life-threatening. The overall odds of any single egg being contaminated are low (roughly 1 in 20,000), but when you’re making a batch of icing that won’t be cooked, even a small risk is worth addressing.
Three Safer Ways to Make It
The FDA is clear on this point: for any recipe where eggs won’t be fully cooked, use eggs that have been pasteurized or use a pasteurized egg product. You have three practical options.
Meringue powder is the most popular swap. It contains pasteurized dried egg whites along with cornstarch and stabilizers, so it behaves almost identically to fresh whites. You’ll find it at baking supply stores and most large grocery chains. Iowa State University Extension specifically recommends it as a “convenient and safe choice for royal icing.”
Pasteurized liquid egg whites come in cartons in the refrigerated section. They’ve been heat-treated just enough to kill bacteria without cooking the protein, so they still whip up properly. Royal icing made with these will taste and perform the same as the traditional version.
Pasteurized shell eggs are regular eggs that have been gently heated in their shells. They’re sold alongside conventional eggs, usually labeled clearly. These are the FDA’s recommended option when you want whole eggs or separated whites for uncooked recipes.
Does the Sugar Make It Safe?
Royal icing is mostly sugar, which leads some bakers to assume the high sugar concentration alone prevents bacterial growth. There’s some truth to this, but it’s not the whole picture. Sugar does lower the available water in a food, making it harder for bacteria to thrive. At saturation (around 67% for sucrose), sugar creates enough osmotic pressure to pull water out of bacterial cells and slow their growth significantly.
However, research on sugar concentration and microbial inhibition shows that even saturated sugar solutions don’t reliably drop water activity below the 0.7 threshold needed to fully prevent all microbial growth. The sugar in royal icing is bacteriostatic, meaning it slows bacteria down rather than killing them outright. Spores can survive, and if conditions shift (say, the icing absorbs moisture from the air), growth can resume. So while the sugar content helps, it’s not a substitute for starting with pasteurized eggs.
Who Should Be Most Careful
For a healthy adult, eating a small amount of traditional royal icing made with raw eggs is unlikely to cause problems. But the risk calculation changes for certain groups. Young children, pregnant women, older adults, and anyone with a weakened immune system are more vulnerable to severe Salmonella infections. For these groups, the safest approach is to only eat royal icing made with meringue powder or pasteurized egg whites, with no exceptions.
This is especially worth thinking about during the holidays, when decorated cookies get passed around at parties and classrooms. If you’re making cookies for a group where you don’t know everyone’s health status, using meringue powder is the simplest way to make sure the icing is safe for everyone.
How Long Royal Icing Lasts
Royal icing made with meringue powder stores well in an airtight container at room temperature for at least two weeks, with some bakers pushing it to four. Icing made with pasteurized liquid egg whites or fresh egg whites has roughly half that shelf life at room temperature, so plan to use it within a week or refrigerate it.
Once royal icing has dried on a cookie, it’s even more shelf-stable because the moisture content drops dramatically. Decorated cookies with a fully dried royal icing coating can last several weeks at room temperature when stored properly.
Signs that stored icing has gone bad include a sour smell and a puffed-up or bloated appearance in the container, which indicates bacterial gas production. If you notice either, throw it out.
Vegan Royal Icing
If you skip eggs entirely, aquafaba (the liquid from canned chickpeas) whips into a convincing substitute for egg whites and produces royal icing with a similar texture. Since there are no animal products involved, there’s no Salmonella risk at all. The high sugar content in the finished icing keeps it stable, and most bakers find aquafaba royal icing lasts about two weeks stored at room temperature in a sealed container. The taste is virtually identical once the powdered sugar dominates the flavor.