This month on Kitchen Geekery, Dr. J. explains the science of royal icing and gives us some tips on how to decorate with royal icing (and how to use those tricky piping bags) - just in time for Christmas cookie decorating!
I’m quite certain that most of us shy away from any and all kinds of cookie decorating this time of year. We want to decorate the cookies, but royal icing can be tricky and then it can get really messy filling a piping bag.
The Science Of A Royal Icing Recipe
Royal icing is easy, right? Simply combine egg whites (meringue powder works too), powdered sugar, a little lemon juice, et voilà!
You aren’t actually done at this point. You can’t just mix the ingredients of royal icing together and then start piping.
Or rather, you could try, but I bet you would end up with a messy flood of icing that doesn’t stay in place on the cookies. It’s more of a glaze than anything else at this stage because you must beat the royal icing for a long time (even 10 minutes) before you can pipe and decorate cookies with it (even if you are flooding, a.k.a. filling in within the piped lines).
The Key To Perfect Royal Icing: Whipping!
Royal icing must spend a lengthy time whipping in your mixer because, just like with meringues, the egg whites must be beaten so the proteins unfold. A little acid, like from lemon juice, helps speed up the unfolding process.
Once unfolded, the egg whites can form a new firm, stable structure that can hold its shape and withhold tiny little bubbles of air. The unfolding and refolding process is the key to why royal icing stays in place without running over the sides of your cookies. Without that final firm structure, you risk having little to no control over how your icing settles on your cookies.
So, do not skimp on the beating. Whip it good!
Tips For Using Piping Bags When Icing Cookies
Using a piping bag makes things so much easier. You can buy them in kits, like this one with four reusable bags (affiliate link) in different sizes. You can also buy kits with different tips (affiliate link) but one or two basic tips are all you really need.
Filling piping bags can be a clumsy, messy, frustrating process, especially for those of us who only pull out the piping kits once a year for the holidays. Here are a few handy tips that I've picked up over the years that make cookie decorating a little less scary:
1. Use A Bag Clip
Once you have cut an opening at the end of your piping bag and fitted it with a tip, I suggest you take a handy, small bag clip like these ones (affiliate link) to clamp the bag shut just above the piping tip. This way, there’s less mess. Professionals like to use the bag itself to block the piping tip by twisting and stuffing the bag into the larger opening of the tip. To each his own.
2. Use a Mug or Glass To Stand Up Your Piping Bag While Filling
When you're ready to fill your piping bag, my second suggestion is stand the piping bag up in a sturdy tall glass or mug, then fold the top edges of the bag over the lip of the mug. This way, you keep the top of your piping bag clean and you don’t need to hold the piping bag while trying to get icing onto a spatula and into your bag.
I suggest folding over as much as half the piping bag and therefore only filling the bag about halfway because if you fill it too full, you will probably end up with icing coming out the top of the bag, and not just the tip. Plus it’s a lot easier to handle a bag that isn’t so full.
3. Scoop Icing in the Piping Bag
To fill the bag, scoop the frosting or icing into the bag, being sure to use the folded edge of the bag to scrape the spatula clean.
4. Twist the Bag Closed Before Piping
When the bag is full, pick up the bag from the folded edge and flip it back upright. Twist the bag just above the level of frosting to seal in your icing and keep the top of your bag clean. That twist is also your handle. Alway grip/squeeze the bag at the twist with your dominant hand. Never squeeze from the bottom of the bag. Your non-dominant hand is used to steady/guide the tip as you pipe.
If All Else Fails... Use Generous Amounts of Sprinkles
Practice makes perfect, but if all else fails and you find that you are still having trouble, cover up your cookie decorating attempts with sprinkles and call it a day because everybody loves sprinkles. Happy Holidays!
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Kitchen Geekery is written by Janice Lawandi. Janice is a PhD-chemist-turned-baker, which is why she loves to use science to understand and solve problems in the kitchen. She is currently working as a recipe tester and writer in Montreal, QC. Visit Janice’s blog, Kitchen Heals Soul, for more baking science and inspiration. You can also follow her on Instagram, Facebook, and Twitter.