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asked November 15th 2013

Fondant covering and Air bubbles

I used butter cream filling and crumb coat and covered in apricot glaze before covering in fondant. I smoothed it and got all the bubbles out and yesterday if was lovely and smooth. Today however when I went to complete the cake there was a very large bulge on the side and after I released the air it seemed to be ok. I had then put a topper on it and used royal icing to secure it and after and hour an air bubble had appeared on top. I really don't know what I'm doing wrong but to make things worse just before my friend came to collect the cake the air bubble on the side had appeared again and fondant had started to crack only getting worse as I tried to work the air out. Does anyone have any suggestions. I also put weight on the cake overnight before covering to expel any air. Help!!!


Hi tmurray

From my own experience I find over kneading the icing will cause air bubbles without fail. I always knead my icing the night before which allows it to rest. Flatten it out as if ready for rolling and place in a plastic bag The following day it requires minimal kneading. The way icing is kneaded can have an effect on how smooth it is when rolled out. Try not to fold the icing when kneading, bring icing to the centre and rotate quarter turn a few times. Folding action forms layers which trap air. Your bubbles may also have been caused by the apricot glaze forming a barrier against the icing and cake preventing proper adhesion. If the icing doesn't stick down properly air can get trapped resulting in bubbles. It's also possible a bubble had formed on the top of the cake which bulged down to the side when the topper was placed. It's important to expel air from the top of the cake using your hands or smoothers before sticking the sides down. Lift the excess icing skirt and gently smooth out from the top if you can see any bubbles. Air bubbles can also form if icing has been rolled out too thick. These are just a few causes for air bubbles, other members may be able add more.


Hi Madewithlove

Thank you for your advice. I used my smoothers and expelled all the air bubbles I could find when I covered it. This large bulge appeared on the side 24 hours after I had covered it and after I got rid of the air it didn't want to stick properly again.
The top of the cake was perfectly smooth and air free but another large bubble appeared shortly after I put the topper on attaching it with blob of royal icing. Could this be something to do with moisture. I have tried all different methods to stop air bubbles and I thought I had won the fight, but clearly not. Would kneading the fondant too much cause this as I have on occasion seen small air bubbles as I roll it but these bubbles were gone when I covered the cake. It was also rolled to 4 - 5mm thick.
I hate to bombard you with so many questions but would you suggest a different sticking agent rather than apricot glaze? Thanks for any advice you can give me.


It may well be the apricot glaze. When I've watched tutorials on other sites I've never seen jam used as an adhesive on a butter cream crumb coat. I use glaze on fruit cakes to stick down marzipan which works fine.
I think the amount of glaze used may have been a factor. As I've said in my last answer, over kneading will form some very large bubbles right through the icing which will persist once the cake has been enrobed.
While at the International Cake show I saw Mitch Turner from the Little Venice Cake Company teaching how to knead icing to prevent air bubbles. Her advice was similar to what I've suggested and that is to knead the icing the night before and knead as little as possible on the day of use. If your crumb coat is set very hard try brushing the cake with a little vodka just enough to make it tacky. I would suggest fine misting with water but you would have to be very careful not to over wet the cake as this could make the icing gloopy. Vodka evaporates very quickly so your icing will not saturate.
I wouldn't use the glaze, I really think this is the cause of your problem. See how it goes by trying the other methods. Have a look also at the icing cakes tutorials here http://www.designer-cakes.com/online-cake-decorating-courses/1-icing-cakes-overview Each lesson shows how to get the best results from your icing. Don't get disheartened, I know it's frustrating and almost everyone suffers with these little niggles. x


Thanks again for your advice I will definitely try your suggestions and look at the links you have given. I really would like to try ganache for a change but not had the chance yet. I do tend to overwork my fondant so lesson to be learned there. I just hope it's ok at the party tonight. The main bonus was that it was at the back of the cake so hopefully it's not too noticeable. :-)

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