If you're just starting out decorating with royal icing (RI), believe me when I say, in the beginning, it can be a real love-hate relationship!
Even now, after almost 5 years of working with it (I made the acquaintance at the end of 2015), on a rare occasion, it still can throw me a curveball! In those moments, royal icing acts so cranky and irritable that I could swear it's going through PMS! Well, reason has it, that it's just suffering under the weather, of course ;-). And don't we all sometimes?!
In any way, I'll help you get the handle on this royalty. We will tame it together and make a sweetheart out of it. You will grow to love it the way I do and be quick to forgive it should it throw you a temper tantrum once in a while. Because, I promise, the majority of times, it will be your very disciplined and compliant friend if you know just how to treat it.
Now let's get to it, shall we? The first thing you need to know, of course, is how it is made. I promise you that's easy enough if you only follow a few simple rules :-). But let me first have a word about the two main ingredients: egg whites and powdered sugar.
Most people make royal icing with dried or pasteurized egg whites or meringue powder because they are afraid of salmonella poisoning. But let me ask you this: If sugar is an excellent preservative - which it is -, and bacteria need moisture to grow in, then how in the world could salmonella contaminate and multiply in dried-to-a-rock royal icing?
If I'm wrong, and you know better, then I'd be happy if you would enlighten me ;-).
Salmonella lives only on the shells anyway. If you clean eggs with vinegar just before you crack them open, you lower the risk to a minimum. Vinegar kills or at least reduces salmonella, e. coli, and listeria. A healthy stomach with enough hydrochloric acid will take care of the rest.
When it comes to powdered sugar, count yourself lucky if you live in a country like the USA, where most grocery stores carry the 10x confectioners' sugar. Here in Switzerland, I have not been able to find anything but 6x powdered sugar, which is just too gritty for intricate royal icing work.
The number before the "x" denotes how often a sugar has been ground/milled. All ground sugar is called powdered sugar, but only the 10x is confectioners', which usually contains a small percentage of cornstarch to keep it from clumping.
At the beginning of my cookie decorating journey, I was battling blocked tips a lot and couldn't put my finger on what I was doing wrong. I thought all powdered sugar should be the same, but oh no! Switzerland, the country of famous chocolates and sweets, was selling me subpar powdered sugar, LOL!
I was thrilled when I finally found an "extra fine" powdered sugar in Austria that seems to be 10x. I still have to sieve it, though, as it still contains a few sugar crystals.
But a strainer/sieve with a fine mesh of 0.5 mm does a great job getting rid of these. The one I use is a German Rösle as shown below.
I found that this sieve is the best indicator of whether a powdered sugar is 10x or 6x. The 10x has to be pushed through the sieve, while the 6x will fall through it with just a light shake.
Most sellers of fine-meshed sieves don't denote the mesh size. And I've seen at least one that says their "fine-meshed" sieve has a mesh size of 1 mm. But these openings would be too large for our purpose. Make sure and ask dealers of other brands for the mesh size before you buy.
Here's a short article about confectioners' vs. powdered sugar.