Royal icing is magic when you're decorating cookies. If you want to make dots or pearl borders, royal icing's your go-to. If you want to create a painterly look, royal icing can do that, too.
Whatever the effect you're going for, royal icing can get you there...as long as it's the right consistency.
Here are four ways you can change up your royal icing to meet your decorating needs, organized from the stiffest consistency to the runniest.
1. Stiff consistency
This icing is good for brush embroidery work, tiny roses or piped pearl or shell borders.
To stiffen basic royal icing, just stir in more sifted powdered sugar, bit by bit. Your icing is stiff enough when it can hold a peak after you quickly lift out a spoon, palette knife or whisk.
Avoid working with teeny-tiny piping tips if you're using stiff royal icing. You'll have to press and squeeze your piping bag harder to push out the icing, which will not end well (think: a ripped piping bag, a giant mess and a frustrated cookie decorator).
2. 15-second or 3-D consistency
This is the most versatile consistency. It's perfect for any 3-D elements you want to stand out from the rest of your piping, but some cookie decorators even use it for outlining and flooding.
15-second icing consistency holds its own, but softens or floods lightly so any peaks smooth out.
Adjusting a basic royal icing into a 15-second consistency is easy: Add more sifted powdered sugar, mix and test. If it's still too thick, add a little water.
It's the right consistency when you run a butter knife or palette knife through it in your mixing bowl and it blends back together in 15 seconds.
If you want to pipe a 3-D shape onto your cookie, test it first! On a flat plate, pipe it out and set it aside for a few minutes to make sure it keeps its shape and settles down. (Also, make sure the flooded cookie surface is totally set before piping on top with 3-D.)
3. Piping consistency
Piping-consistency royal icing needs to be thick enough to keep the runnier flooding royal icing at bay and create different sections in a cookie design. But it still has to be flexible enough to pipe out any way you want. This consistency can also be used for adding piped details on top of pre-flooded, set cookies.
There's no easy way to tell if this royal icing is the right piping consistency while it's in the bowl, so you need to test it! Too stiff and your piping will break up. Too wet and it will flood out. It takes a bit of trial and error, but just keep adjusting until you get it right.
It sounds obvious, but piping outlines or details onto cookies is totally different than piping on cupcakes. You need to anchor your royal icing onto your cookie (touch the tip to the cookie and pipe a little out so it sticks) before lifting up and basically piping in mid-air so the line of royal icing falls gently onto the surface. This really helps keep those lines sleek.
4. Flooding consistency
This is a thinner, runnier icing that fills in (or "floods") an area outlined in piping or 15-second consistency icing. It's the fastest way to a flawless cookie finish, but only if the consistency is right. Make it too runny and you'll be left with a mess as it flows over your piping; make it too stiff and it won't spread or set smoothly.
Another great thing about flooding icing is that you can use it to add painted effects, like these poka dots. Once you've flooded your cookies, take a contrasting color royal icing (also in flooding consistency) and pipe in a pattern. Both royal icings will begin to settle and smooth over, creating a wonderful seamless look.
To make royal icing with this consistency, add a small amount of water to your basic recipe until it's a bit runnier than honey. If you scoop some up with a spoon and plop it back into the bowl, you should see the icing blend back together in a few seconds.
For better control, use a small squeeze bottle rather than a piping bag. Smaller ketchup-like bottles work well because of their tiny nibs.