How To Achieve The Perfect Icing Consistency For Iced Cookies

Sugar cookies can be made iconic with their icing — the crowning glaze that embellishes them into a mainstay for the holiday seasons, parties, or when a sugar craving hits. But the icing has to be the perfect consistency to tie the beautiful display together. You certainly don't need a runny mess spoiling your cookies after whiling away hours baking them, and this is how you avoid that at all costs: By thinning your icing.

Royal icing is often used for icing cookies, and it's made with confectioner's sugar, egg whites or meringue powder, and water. It ends up at a stiff consistency after whisking, but if you want to apply it to your cookies, add water to thin it out. To do this, set about half of the icing aside after whisking and add water to the rest. You'll know it's ready when it can spread easily atop a cookie but remain firm enough not to trickle off its edges.

Alternatively, you can apply the 15 to 20-second icing rule where you scoop a bit of the icing up and then plop it back into the icing bowl. The icing should smooth itself within 15 to 20 seconds to indicate it's ready. If it turns out that your royal icing is too runny, use the stiffer icing you initially set aside and mix a spoonful or so of it with the overly runny one. Otherwise, add a few more tablespoons of icing sugar or cornstarch until it reaches the right icing consistency.

Alternatively, you can use powdered sugar icing or glaze or a mixture of confectioner's sugar and lemon juice as we did in our lemony sugar cookie icing recipe. Unlike royal icing, it doesn't contain any egg whites or meringue powder, is simple to whip up, and makes achieving the right consistency for icing your cookies easier. The biggest downside is that it may pose problems with maintaining its consistency, thus iced cookies with royal icing may sometimes look prettier.

To get the right consistency, add more water to your icing or glaze until it's runnier. However, be careful when adding water, as too much of it will make the glaze overly runny, which will require plenty of confectioner's sugar to remedy. To test, apply some of the glaze onto a cookie and if it smoothes itself out within 30 seconds, you've got the right consistency.

You can also use lemon juice alongside water to thin royal icing. Our recipe for sugar cookies with royal icing is one example of how to do this, but you'll have to continually taste your glaze to ensure that the bitter and sweet flavors balance. Also, if reusing your icing after storing it in the fridge or freezer, let it come to room temperature or defrost before determining if it's the right consistency for icing. And, perhaps most importantly, wait until the cookies are baked and cooled completely — because warm cookies will melt your icing — before proceeding to ice your cookies into beautiful holiday treats.