How well you can decorate your cookies comes down to one thing – Icing Consistency. Royal icing is versatile in that it can be very stiff or very runny, depending on the amount of water you add to it. Understanding how to dilute your icing to the consistency you need for specific designs is the first step in making amazing cookies.
Cookie decorators use the term “15 second icing” or “20 second icing”, etc. You may be wondering, “what does that even mean?” The number of seconds it takes for icing to settle is what we are referring to. The smaller the number, the runnier the icing. So a 5 second icing is going to be very runny and a 25 second icing is approaching a very stiff consistency.
If you use my royal icing recipe, the consistency you are left with once the icing has been mixed, is going to be a stiff consistency. This stiffness straight out of your mixing bowl is appropriate for royal icing designs that need dimension. For example, piped roses or other flowers have to have a stiff icing to hold the petal shape. From this consistency, you will add small amounts of water to thin it to your desired consistency. My icing recipe can be found here.
Let’s look at this in a little more detail:
This is my icing after mixing. It’s stiff, holds a peak, and is slightly “wet” which allows for a smooth piping detail. If your icing is too dry after mixing, your piping details may look a little dry. You can add a tiny amount of water to the mix to make it a little smoother.
This icing consistency is perfect for outlining cookies, writing letters and numbers, and can be used for more 3-D designs such as roses and other flowers, and holds it shape well for piping edge designs like shells, rick-rack, smooth shells, dots, rope, etc.
From the stiff icing, you can begin to add water to thin your icing.
When you add water, add very small amounts at a time to avoid over-thinning. I like to use a dropper. Some cookie decorators prefer to use a spray bottle and spritz the icing with water a little at a time.
Add your water a little at a time and mix to combine.
Next you are going to drag your spatula through the icing to make a “cut”.
Now, the time it takes for this “cut” to smooth out and go away is where the “seconds” come in. Once you make your “cut”, start counting in seconds until the line goes away. If it never goes away, your icing is still on the stiff side. If the line goes away in 5 seconds, then you have “5 second icing”. If it takes 15 seconds to go away, then you have “15 second icing”.
A good consistency to use for most cookies is 15 second consistency. This consistency is thin enough for flooding cookies but stiff enough that it doesn’t run off the cookie without piping a border in a stiffer icing and can be used for some detail work. Less than 15 second is only good for flooding. 10 second icing is good for wet-on-wet designs where you need a thin icing that will stay wet long enough to pipe other colors on top of it and allow them to settle together and become smooth. Icing that is greater than 15 seconds is good for piping a border “dam” to hold flood icing on your cookies and can be used for some detail work.
When you flood cookies, your icing should be thin enough to settle once you have piped all of the icing on to the cookie, but not so runny that it runs off the cookie. If your flood icing is too thin (like a 5 second consistency), you will need to use a stiffer icing to first pipe a border around the cookie to make a dam to hold the runny flood icing.
As you can see in the above image, the icing shows the piping lines as I pipe the icing onto the cookie. But after a few seconds, it settles down and becomes completely smooth on top.
In my Royal Icing Recipe video, there is a quick over view of icing consistency following the recipe. You can watch that video here: