How to avoid Royal Icing Craters When Decorating Cookies

Hey Besties! If you decorate sugar cookies, you’re inevitably dealt with royal icing craters…ugh, the dreaded craters! It is incredibly frustrating when you’ve worked so hard on your cookies only for the icing to collapse and ruin the look of your cookies. Well worry no more, I’ve cracked the code! Read on to learn why craters happen and what you can do to avoid them!

Since this is an issue so many cookiers run into, I spent a lot of time researching why this happens and then conducting what I called a ‘crater study’. I worked in research years ago and admittedly, the nerd in me kind of had fun organizing my experiments.

Why do Royal Icing Craters Occur?

In order to know how to prevent royal icing craters, first, we need to understand why they occur. They most commonly occur in small areas, not a larger flooded area. The reason small areas are prone to craters is because of surface tension. In these small areas, the edges dry faster and basically put weight on the middle, causing the icing to collapse, or crater.

Secondly, if you are icing over a flooded area, you should be adding these details once the flood crusts, not after it’s completely dry. If you wait until the initial layer is completely dry, it will pull moisture from the next layer, causing the new icing layer to crater.

These are main reasons cratering occurs, so let’s jump into the crater study and how we can prevent cratering!

Crater STudy

I’ve read and heard of many different theories on how to prevent cratering so I was determined to get to the bottom of it…for the sake of cookiers everywhere.

I used a very basic butterfly cookie design as my test subject to study the craters and studied many cookies! Here are the experiments I ran, based on several theories:

• Using a 12 second flood
• Using a 20 second flood
• Adding squiggly lines as a support structure before flooding the new area

Since many theories also involved how the cookie dries, I tested several different quick dry methods as well:

• Airdry
• Using the oven light, door cracked for 15 min
• Heating oven to 170 degrees, turning it off, leaving the door cracked for 15 min
• Heating oven to 170 degrees, turning if off, leaving door shut for 10 min

Crater Study Results

The study was very interesting and yielded some great results! Here are my takeaways:

• The icing consistency did not make a difference. Regardless of whether I used a 12-second or 20-second consistency, the results were the same. So, consistency alone is not the issue.
• Adding squiggly lines as a support layer before filling in your area, did help! If you have not heard of this, here is a picture of what I mean:

Studying the quick dry methods was also eye-opening!

• Airdried cookies resulted in the most cratering, which was not surprising
• Putting cookies in the oven just using the oven light as heat did help with cratering, but was not the best method.
• Putting the cookies into an oven that had been heated to 170 with the door closed for 10 min produced the worst results of the study. It was simply too warm and basically melted the icing and led to more cratering.
• Putting the cookies into an oven that had been preheated to 170 with the door CRACKED for 15 min produced the best result, resulting in NO cratering!

Recommended methods to avoid royal Icing Craters

Given everything tested, here are a few recommendations I have to prevent cratering!

• Your timing of adding layers of icing makes a difference! It’s best to add new layers when the existing layer of icing has crusted. If you let the flood layer completely dry, there is a good chance your next layer may crater. This is because the dry layer pulls moisture from the new layer on top of it, causing it to collapse. So, flood your cookie, let it crust or use one the suggested quick dry method below, then add your details on top.
• If you only want to airdry, use the squiggly lines to add a support layer before filling in your area. Even when airdrying, this yielded VERY good results!
• If you are willing to use your oven to help quick dry your icing, you do not need to add the squiggly lines. Simply decorate your cookie, place it in an oven that was heated to 170 degrees, heat off, door cracked, for 15 min. This method produced the best results, check out this beautiful butterfly!

Now, there is one more method that MANY people recommend but I did not include in this study simply because it requires an additional piece of equipment: a dehydrator. I can tell you, a dehydrator is a game changer when it comes to preventing cratering and also adding shine to your cookies. If you’re ready to make that leap, THIS is the dehydrator I recommend. I have a whole post HERE, all about using a dehydrator and why I use one with every cookie set I make. But in the interest of wanting to help cookiers without having to make an investment, I hope my crater study and results are helpful for you! Armed with these recommendations, royal icing craters should be a thing of the past!

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