Gas Bubbles Forming Under Fondant

Decorating By dyrinella Updated 23 Apr 2014 , 2:03pm by Hamaranpuu

dyrinella Posted 28 Aug 2009 , 7:05pm
post #1 of 55

Hi all,

I occasionally have a problem with gas bubbles forming under the fondant on my cakes. The fondant will be nice and smooth with no apparent flaws then the next day there will be a huge bubble in one area, like either the top or the side. When the bubble appears is random. The big problem is this happens after the fondant is set and drying, so I can't smooth it out. Does anyone have any idea why this is happening?


54 replies
Texas_Rose Posted 28 Aug 2009 , 7:10pm
post #2 of 55

Cake farts! icon_biggrin.gificon_biggrin.gificon_biggrin.gif

No, seriously, there are some gases that need to escape from the cake after baking. If you let the cake settle overnight before you put the fondant on, you should be able to avoid the dreaded air bubble problem.

-K8memphis Posted 28 Aug 2009 , 7:19pm
post #3 of 55

Not really--just that what you said, air gets trapped so what I do is on purpose after cake is all dressed for the party-- I stick a pin through to the cake and leave a little hole open in a unobtrusive spot in each layer of cake on each tier. It helps me to avoid that.

Idea for you...

vnm42101 Posted 28 Aug 2009 , 7:23pm
post #4 of 55

Sorry I can't help you and I am going to add to your question because I was about to post something similar when I saw your post. I've gotten the same thing with the last several cakes I have made. The last cake I made (the clothesline baby shower cake), I baked two days ahead of torting, filling and icing. I baked them, let them cool and then wrapped them in saran wrap and let them sit on the counter. But I still got a huge bubble. I need help because I have to do a wedding cake in 3 weeks and this CAN NOT happen again. Thanks and sorry for taking over the post.


brincess_b Posted 28 Aug 2009 , 9:01pm
post #5 of 55

it can also happen with temperature change - like if you fondant a cold cake.
i think it can also happen if your fondant isnt actually stuck to the cake - like if your bc is too well crusted.
if you pop with a pin (at an angle is aparently less noticeable than straight on) you will hopefully be able to fix it.

dyrinella Posted 28 Aug 2009 , 10:20pm
post #6 of 55

Hi all,

Thanks for the info. I appreciate it, but it really does not solve the problem. When I cover the cake it is cold. Usually I bake a cake and then refrigerate it overnight, then torte, fill, frost, etc the next day. The cake is cold out of the refrigerator when I cover it. Maybe that is the problem? I thought maybe so but it looks like Vivian is having the same problem with a room temperature cake. I also know that you are supposed to chill a cake before you cover it as it makes it easier. With a shaped cake you definitely are to do that. If you watch the DVD made by Mike's Amazing Cakes, they chill the cake at each phase.

Also, once the bubble has happened it is often too late to poke a tiny hole because the fondant has started to dry. So I have a dried bubble on the cake. Thoughts?

brincess_b I think you have some good points. I am pretty sure it has to do with temperature. At least I thought that until I heard Vivian's reply. Also, I have taken a could cake, added the fondant, refrigerated it again, and pulled it out the next day to find the gas pocket. So maybe it it not temperature related?

Can anyone who has never had this happen tell me the exact steps they use when covering a cake so I can compare notes?

Thanks again all!

-K8memphis Posted 28 Aug 2009 , 11:14pm
post #7 of 55

No because there really is no solution to this issue that I know of.

If someone says it's from previously frozen cake I have seen it in never frozen cake, etc etc etc. The only common denominator I know of is that it is iced cake. I've seen them form as I ice the cake.

I have been studying this phenomenon for decades. I cannot determine a common denominator except it is trapped air.

It is hopefully averted in advance with a well placed bunch of holes or the bubble forms & then is popped. I've never heard of any good explanation or cure other than that.

I believe it's Leah who places something heavy on the cake to help the air escape well in advance of it being iced.

-K8memphis Posted 28 Aug 2009 , 11:18pm
post #8 of 55

By the way they form under every kind of buttercream too.

-K8memphis Posted 29 Aug 2009 , 12:00am
post #9 of 55

Great write up in the paper. Pretty cool, Cakebuddy.

Mug-a-Bug Posted 29 Aug 2009 , 12:34am
post #10 of 55

I always get these icon_cry.gif buttercream or fondant

If the fondant is hard I spray it with a little water, lift it off the cake and resmooth it down. This wont work if the fondant is REALLY hard. You have to try to "catch" the bubble asap. This works for me thumbs_up.gif Poking with a pin never helped me, but I know a lot of people have had success with it.

Don't know what causes those darn "cake farts" icon_confused.gif

dyrinella Posted 29 Aug 2009 , 2:50am
post #11 of 55

Hi all,

I want to thank you all again for taking the time to reply to this post. I have been in the business for years and have never been able to keep this from happening from time to time. I have had it happen once with just buttercream, so yeah, that sounds like the common factor.

The next few fondant cakes I do I am going to leave gaps in the buttercream. If that seems to help I will let you all know.

Again, thank you all for your time. If nothing else I am glad to know that I am not alone in this.

BTW - I just took my latest problem child, which had hard fondant and a bubble, and smoothed over it with Crisco. This helped quite a bit but it is still obviously not perfect.

sugarshack Posted 29 Aug 2009 , 5:26am
post #12 of 55

Dyrinella, I think your problem may be the cakes being iced when cold, etc and then sitting out after the fondant is applied. Condensation is going on in there and causing the blow out. Lots of folks put the fondant covered cake back in fridge so as not to have that temp change; and they seem to have less bubbles from what I read.

and YVM, I think you are getting them because of the plastic wrap. The cakes sweat in there and when you take the plastic off the surface is still damp from that. If you wait a while with the cake uncovered in a cool room till the surface dries off; it should help. That is what i do. If I ice a cake right out of plastic, I will sure fire get a blow out.


madgeowens Posted 29 Aug 2009 , 5:48am
post #13 of 55

sugarshack.........if you put the fondant on a chilled cake and then return it to fridge.......when you get it out to serve.....what can you do to prevent the outside condensation on the fondant? sorry to hijack a wee bit

sugarshack Posted 29 Aug 2009 , 6:09am
post #14 of 55

Madge, I really do not know because I do not use this process although I know tons of folks do. I would assume you are going to have wet fondant! I guess if it sits a few hours it would dry? But then I would worry about a blow out! ACK!

I know lots of peeps use perishable fillings and meringue buttercreams, and they keep their cakes chilled till delivery time. I honeslty do not know how they handle the condensation.

I fridge nothing; I don;t have room and the heat and humidty just too bad where I live.

madgeowens Posted 29 Aug 2009 , 6:19am
post #15 of 55

I just find it so much easier to apply fondant to a cold cake, if you have to take it back off and put it back on, it doesnt goof up butter cream.....last time my fondant started to sweat for the first time and now I am afraid to use fridge,

sugarshack Posted 29 Aug 2009 , 6:22am
post #16 of 55

i flash freeze my bc cake for 5-9 minutes before I apply the fondant. then no more chilling. period. that makes the Bc nice and firm to apply your fondant but cake is not chilled all the way thru, so condensation not an issue for me.

madgeowens Posted 29 Aug 2009 , 6:41am
post #17 of 55

that would explain this last cake having was in the fridge all day where are others only half hour or so ...thank you so much....
your cakes are flawless .............really amazing.....

sugarshack Posted 29 Aug 2009 , 6:43am
post #18 of 55


for me and my cakes and where I live: cake+cold=disaster

Thank you for the nice words too!

dyrinella Posted 29 Aug 2009 , 7:38pm
post #19 of 55

Ok, so it sounds like cold cake = bad. I usually work on a cold cake since I do a lot of carving and that makes it a lot easier. I have a carved wedding cake this weekend so I am going to do it at room temp and we shall see how it goes.

Thanks all.

sugarshack Posted 29 Aug 2009 , 10:36pm
post #20 of 55

Sorry, I do not want to mislead.

LOTS of people ice and fondnat cold cakes with no problems at all. It does not work for me, for some reason.

Many people use cold cakes to carve, and I do not think that is a problem. I would try to let it come to room temp before i did the final ice or fondanting; because I know I would have problems in my environment if I did not.

But like I said above, lots of folks keep their stuff chilled thru the whole process and do fine.

I think it varies by the recipes used, your climate, the humidity of your cooler, etc. We each have to go thru some trial and error to find what works for each of us.

I did not mean to imply that cold cakes are a no-no for everyone; just that in my circumstances I have found issues with it. Please do not stop doing something that works for you.

michellesArt Posted 29 Aug 2009 , 11:15pm
post #21 of 55

i agree with K8 though as i worked on room temp cakes, baked the day before and the next day there were bubbles all over my cakes (i had made 6 6" for a wedding and only one was gas-less) i think they just plague anyone, anytime. nasty cake gas wrecking havoc on our pretty cakes! i'm going to try the pin trick next time. icon_smile.gif

dyrinella Posted 30 Aug 2009 , 1:04am
post #22 of 55

Ok, maybe it is the use of buttercream. Has anyone had this happen with a cake covered in jelly and then fondant?

Again, thanks all.

madgeowens Posted 30 Aug 2009 , 4:57am
post #23 of 55

Would fondant on jelly even work? I would not want to try that.

When I carve a cake thats different, because its only crumb coated to the carving point.....I think a quick chill to cover is ok any longer like sugarshack says its chilled thru and then you get the moisture problem.

-K8memphis Posted 30 Aug 2009 , 1:07pm
post #24 of 55
Originally Posted by dyrinella

Ok, maybe it is the use of buttercream. Has anyone had this happen with a cake covered in jelly and then fondant?

Again, thanks all.

Not that I can remember. It's worth a try.

But the fondant is still going to trap air which to me is the greater point not stickyness.

So far the trapped air has trumped sticky-ness.

To me it's the nature of the air in the cake rather than any surface adherence issue.

The condition of the surface does not eliminate the air, the fondant is still flexible.

dyrinella Posted 30 Aug 2009 , 1:23pm
post #25 of 55

I am just thinking that the jelly has a really sticky surface so things are more likely to fully stick and maybe there is less of a chance of air.

I have to admit that I feel so much better hearing from all of you that you have similar problems. I have been in business for years and work with fondant all of the time and it gets embarrassing to admit you have basic issues, you know?

hamie Posted 30 Aug 2009 , 1:36pm
post #26 of 55

I really think the problem is wait time. You have to let the cake settle or place a heavy book on it to prevent the air bubbles.

I had air bubble problems for a year, until I changed by caking days. I bake on Wed, fill and crumb cake on Thurs, finish decorating on Fri. The overnight settling got rid of all of my air problems.

If you don't have time, place a heavy book on the crumb coated cake for a few hours to force the air out.

good luck

dyrinella Posted 30 Aug 2009 , 2:10pm
post #27 of 55

Thanks for the advice. I was just thinking of trying that amount of wait time. I am guessing that after you crumb coat you do not refrigerate. Is that correct?

That book idea is really clever!

chanda Posted 30 Aug 2009 , 3:36pm
post #28 of 55

Just to clarify...I am making a cake today that I will freeze. The wedding cake is due the 12th (Saturday). So you all think I can thaw on Wednesday night....fill and crumb coat I wrap with saran to prevent it from being stale and put a book or tile on top...then fondant and decorate on friday?

dyrinella Posted 30 Aug 2009 , 3:51pm
post #29 of 55

Chandra, that should be fine. If you are worried about it getting dry just brush the inside with a little simple syrup. If you loosely put some plastic wrap over the top after the crumb coating is set then all the better.

luddroth Posted 30 Aug 2009 , 4:07pm
post #30 of 55

Here's another thought on the "cake fart" problem. I've found that dense cakes tend to "fart" less than cakes that start out with more air in them -- regardless of temperature changes. A box cake, for example, ends up quite light = a lot of air in the cake. A mud cake, a pound cake, or homemade moist yellow cake (Toba Garrett's recipe, for example) has less air to start with and, therefore, less air to blow out as the cake settles. What do you all think?

Quote by @%username% on %date%