How To Make Meringue Powder-Based Icing As Shiny As Possible

If you're a novice cookier, you've likely spent no small amount of time scrolling Reddit's cookie subs, drooling over the gorgeous sugar cookies of confection veterans. And if you're like many people, you're jealous of that glossy royal icing you see in the pictures. The culprit is probably your meringue powder: Even if you use a high-quality meringue powder, it has a satiny finish at best. 

So how do you give your cookies that enviable glow without resorting to salmonella-friendly fresh egg whites or watery, whip-resistant boxed egg whites? Two words: corn syrup. Corn syrup helps recipes retain moisture and avoid crystallization, both of which can yield dull results when you're talking about royal icing.

Note that we're talking about sweet, wholesome(-ish), naturally derived corn syrup here. High-fructose corn syrup is a different beast. Makers add enzymes to glucose-based natural corn syrup to change its chemical makeup and introduce fructose. Neither is inherently dangerous in moderation, but they're also not the same thing. High-fructose corn syrup is much sweeter and not typically commercially available, at least in its pure form. The corn syrup you need for royal icing is available in most grocery stores (and many convenience stores) under brand names like Karo and Crown (or in dozens of store brands).

Corn syrup is an inverted syrup, which is a kind of liquid sugar with different properties than table sugar (thus, it's inverted). In North America, that inverted syrup is typically light corn syrup, whereas European readers can opt for liquid glucose. Honey or golden syrup would probably also work, though they might impact the color and flavor.

Inverted syrups inhibit the formation of crystals. One example of crystal formation can happen in honey over time. When that happens, any unaffected honey remains bright and clear, while the crystallized honey is dull and opaque. The same principle applies to your royal cookies: Crystallization leads to dull icing. 

Corn syrup also promotes hydration, which in small amounts helps the icing retain moisture, lending it a softer texture and ensuring it dries smoothly, which reflects light more efficiently. But using too much could cause your icing to dry too slowly or with craters and pits, which can also dull the shine.

Adding corn syrup will get you most of the way there, but other mistakes can still dull the shine of your gorgeous iced bakes. First off, opt for a high-quality meringue powder. Genie's Dream is a popular option, but use whatever works best for you.

You should also ensure your cookies dry in a reasonable amount of time. Air drying is the most convenient method for most people. It takes six to eight hours, but there's no special setup. Just put the cookies out of the way, cover them if you need to, and go about your day. If they get dull after air drying, you have a moisture problem. When you make your next batch, you have a couple of options to ensure faster drying. You can run a dehumidifier in the room with the cookies. If you don't have one, you can also set a table fan to blow over the cookies for the first two hours. Just keep it on low at first. 

And if you have one, many cookiers swear by dehydrators. They dry that top slick of icing so fast that the icing retains its puffiness, whereas they tend to slightly flatten while air drying. Just put the cookies into your dehydrator after each layer of icing. Run it on low for 15 or 20 minutes, then let it cool for 10 or 15 minutes to prevent cracking.