Troubleshooting Royal Icing: Cratering

Cratering in royal icing cookies can be a frustrating issue for cookie decorators. You’ve spent time meticulously decorating your cookies, only to find unsightly craters forming over time, ruining your hard work. It’s not something that everyone will notice or care about, but you, as the decorator, certainly will. I know we also fear judgment from other decorators when we have issues like this but fear not (or I guess, fear a little less!)! In this blog post, I’ll dive into the causes of cratering, explain what I believe causes it, and provide you with some effective tips to avoid this common problem. As with all cookie decorating, this is my way, not the *only* way, and it’s very possible I’m missing something, or due to differences in equipment, environment and technique/recipe, we are not operating from the same baseline- so read through these points carefully and use your judgment when trying out different things.

BONUS: all these tips/tricks for reducing craters is also going to help you achieve puffier icing- like the W monogram- I know we all love that.

Section 1 – What is Cratering in Royal Icing Cookies?

Cratering refers to the formation of small depressions or pits on the surface of royal icing cookies during the drying process, making it particularly frustrating because your cookies look fine as you work on them, and as it dries, these little craters start to form, and it becomes difficult to fill them in later. It’s a pretty common issue, and for most people doing cookies for fun, this isn’t a huge problem. But if you’re looking to take your craft to the next level, it can really be unattractive. 

Section 2 – Causes of Cratering

In general, cratering seems to happen because the icing is not structurally sound – this can be due to a variety of reasons:

• Consistency is key: If the royal icing is too thin or runny, it can lead to cratering. Thin icing is more prone to trapping air bubbles, resulting in a bumpy surface, and if they are not popped, some of these can turn into craters.
• Sneaky Airbubles: It’s normal for your icing to have some air bubbles. Some recipes/techniques have more air bubbles, and if you work with our recipe, you should notice less air bubbles. Generally, a looser base icing results in more air bubbles.
• Under or over mixing icing: One of the components of royal icing is meringue powder (or egg whites..) and as they get whipped, we introduce air into them. Undermix, and your royal icing looks translucent and is structurally weak. Overwhip, and you’re giving too much volume to the egg proteins via air, causing the structure to weaken in a different way. Overmixed icing usually looks porous when dry, and sometimes will not even fully dry and be soft/brittle.
• Oversaturating with food color: The more food color you use, the greater chance of the icing breaking down, causing structural issues. You can usually tell the same way as overmixed icing: it becomes porous or brittle as it dries.
• Not enough Icing: Even larger areas can crater! If you see a flood base sinking in the middle, that’s one form of cratering and usually a result of not having enough icing in the area. When you pipe small areas, you also want to ensure there is enough icing.

Small hearts on eyemask cookies

Section 3 – Tips to Avoid Cratering

• Consistency is Key: Achieving the right icing consistency is crucial. If your icing is too thin, it’s more likely to trap air bubbles. Adjust the consistency by adding small amounts of powdered sugar until you reach the desired thickness. Make sure to keep their icing as thick as possible to reduce cratering.
• Reducing air bubbles: I mention above that some recipes/techniques contain more air bubbles. If you use a recipe that has obviously visible airbubbles, tap your bowl on the counter to help the air bubbles surface, and pop them. You can also let your icing sit for an hour to allow the air bubbles to rise to the top before using it. IF you pipe with a larger piping tip, some of these smaller air bubbles might sneak through. If piping with a smaller hole, more air bubbles will get popped as the icing is forced out of the piping tip. You’ll want to find a balance between different piping tip sizes for the particular application – I personally use tipless piping bags and trim the tip to a size that works for me.
• Pop your air bubbles: After flooding the cookies with icing, gently tap the cookie on the counter and use a scribe to pop any visible air bubbles. This technique helps release trapped air before it causes craters.
• Squiggle layer before piping: My friend Corianne uses a technique where you put a squiggle of thicker icing down under an area that prone to cratering. BTW – learn all her techniques in her book HERE.
• Invest in a Dehydrator or tabletop fan: Consider using a food dehydrator or tabletop fan to speed up the drying process, so your icing dries before it has a chance to crater Dehydrators provide a controlled environment, reducing the chances of air bubbles forming and resulting in a smoother, puffier, shinier finish.
• Drying between layers: I have heard some really mixed experiences with this- usually, if you have icing that’s thick enough and is placed in front of a fan or in a dehydrator right away, it should not crater. If those things don’t work, then consider layering right over crusted icing instead of waiting for the base icing layer to fully dry before adding layer 2. HOWEVER, some people swear that piping over fully dried icing works better for them – but honestly, I feel that thicker consistency and a tabletop fan should really solve most cratering issues.
• Use icing transfers instead: If you have tried everything and still struggle with craters, consider making royal icing transfers on acetate – these are also great to prep months in advance!
• Other things: I’ve heard about poking holes in your base layer before adding your next layer to reduce cratering, I have not tested this myself and can’t comment.

Section 4 – In Conclusion

Cratering in royal icing cookies can be frustrating, but with a better understanding of the causes and the right techniques, you can avoid this issue and achieve that perfect puff. Remember to mix your icing carefully, achieve the proper consistency, allow ample airflow when drying, and using helpful techniques like the squiggle method. By implementing these tips, you’ll be well on your way to creating decorated cookies that are free (or at least mostly free, we aren’t perfect) from craters.

I offer online, go-at-your-own-pace video courses that show you how I make icing and get it to the right consistency for various techniques (flooding, details, florals and more). Check them out HERE.

If you have any additional insights or questions, don’t hesitate to leave me a comment below. Happy decorating!