Fondant And Buttercream Bulges/air Bubbles
Decorating By amysue99 Updated 25 Oct 2014 , 5:08pm by rearly
I know there have been tons of posts about this, but I'm getting frustrated. I am consistently getting air bubbles under my fondant and buttercream and small bulges at the mid-seam. But I'm trying to do everything right! Where am I going wrong? Here is what I'm doing:
1. Cool cakes completely
2. Fill with stiff buttercream dam, about 1/4" filling. Very thin crumbcoat
3. Let rest overnight on counter, weighted for smaller cakes
4. Ice
5. If using fondant, flash freeze (per Sugarshack) and cover.
What is going wrong? Someone please help!!!
I wish that I could help but I am completely stumped. 
You use the very same method that I use to avoid those problems...so I just don't know.
I'm anxious to see what some of the others have to say.
The only difference I can see from what I basically do, is that you're crumb coating before the settling process. I fill, let settle, only then do I crumb coat. The whole purpose of settling is for the cake to compress from its own weight, forcing any excess air out. Why put a seal or barrier up that would keep the air and gases from getting out?
Yup...not stiff enough dam for the buttercream filling. I crumbcoat after filling and rarely have any issues. The only time I have a buldging issue is when I don't let the cake settle long enough (sounds like you are letting them settle long enough) and the only time I have bubbles in the fondant is when I rush the coming to room temp process. The "flash freeze" thing may be why you are getting bubbles. After covering with fondant I try not to ever even have to refridgerate my cake because I will almost always get a bubble as it's coming back to room temp. As for the buldge, all I can think is that your dam is not stiff enough. Oh! When you come back to them after settling are you checking to see if it's overflowing and smooth out the sides again? I usually smooth out my sides, let it crust again, and then do the final coat of buttercream or fondant. One more thing...if you know you routinely get bubbles, watch your cake closely the first two hours after covering (the fondant is firming up during this time) and as the bubble forms just smooth it out before it gets too big...the few I have had I was able to catch when they were about the size of a quarter and just smoothed them right back down. Hope any of this helped!
Cat
I read a post (on here actually) that said that if you use cornstarch to roll the fondant (instead of powdered sugar) that there is a yeast agent in there and that makes those air bubbles. I saw on youtube a lady that sprays here butter cream with water to get a tighter bond between her icing and the fondant, that idea seems interesting. I use cornstarch and get bubbles also myself I use the pray for the best method lol!
This week I used virgin ice fondant for the first time (always use satin ice) the difference when I got the air bubble with this fondant is that when I pierced the air pocket and flattened it out the fondant was still pliable and didn't crack at all so the repair was perfect.
My dam is pretty stiff - almost able to mold it with my hands - and I do clean up any bulging that happens during the settle. I will eliminate the early crumb coat and see if that helps. Also, I usually apply fondant and then begin decorating. I will start giving that firm-up time. I have been able to fix the air bubbles by smoothing them out, but I usually have to remove the bottom border to do so. Thanks for the advice! Hopefully this will help end my problems.
What about air bubbles that develop in buttercream even after sitting overnight (or longer)? I've had 2 or 3 cakes recently to develop air bubbles in the buttercream and I'm not sure of the cause.
One was a wedding cake that was filled/dirty iced on a Thursday, frosted and stacked on Friday and decorated on Saturday, the morning of the wedding. No air bubbles to be seen. Later when I viewed the wedding pictures where they cut the cake, a bubble had developed in the top tier on the side. The only cause I could figure was it was an outdoor wedding and the heat index was about 100. I assume the cake heating up caused the air bubble to come out.
The next cake was for a birthday party. Same process as above except the cake was totally decorated and stacked and ready to go the evening before it was due. Again, no air bubbles in sight. After we drove very, very slowly down a very, very bumpy gravel driveway to deliver - one air bubble developed in the side and cracked the buttercream. Fixed that one the best I could and then later (again viewing party pics) saw that another bubble/crack had developed on the front after I left. I assume the bouncing down the gravel driveway caused it.
Used SPS for both cakes, so they were very sturdy. I hope someone can give some insight! These air bubble problems are giving me fits - not sure what to do to fix it!
Yes, I had that problem as well. Had a bubble develop on the front of a cake (no way to fix or hide) after the car ride. Also used SPS. Cake had been sitting at room temp since the night before. I assumed it was from the heat. Tried to keep the car cool, but some things just can't be controlled.
Amysue, I am having similar situations here. Have you changed anything about your process recently? New recipes for your cakes or butter cream? I have been working on this and I think I have it narrowed down to my BC. Just a thought...oh and if you figure it out please let me know. I am just about on the verge of a meltdown with this issue 
I'm absolutely dying to know why this happens too. My theories on why it happens: (1) refrigerating causes condensation beads (when the cake returns to room temperature) under the buttercream or fondant which causes the bubbles (2) maybe using cornstarch with fondant is the problem because of the chemical reaction. I'm going to try using powered sugar next time. I've heard of someone putting small straws into the fondant covered cake to let the air escape. Hopefully together, we'll all figure this out one day!
...(1) refrigerating causes condensation beads (when the cake returns to room temperature) under the buttercream or fondant...
That's not possible. A cake cannot sweat under frosting.
Science lesson: Cakes do not sweat. Any moisture you see on the outside of a cake, frosted or otherwise, is not moisture coming from the cake...or from the fridge. It is the humidity in the warm air outside of your fridge, condensing on your cold cake when you take it out.
So, the humidity in the air can condense on your frosting or fondant. But it can't travel through frosting to get underneath it on your cake.
Water takes different forms depending on its temperature, from steam/humidity at the warm end, liquid in the middle range to solid/ice at the cold end.
When the humidity (warm/gas) in the air in your room hits the cool of your cake, the temperature changes the gas to a liquid which accumulates on the cool cake surface.
So, the cure for decorated cakes sweating when you take them out of the fridge is to prevent the humid air from getting to your cake. If the cake is in a box when you take it out, the humid/warm/gas cannot reach the cool surface of the cake. It will hit the outside of the cool box and condense there, leaving your cake surface perfectly dry. The cake will be safe as it comes to room temp.
So, if your cake is already frosted or fondanted, the frosting actually acts as a barrier (just like the box does), preventing the humidity from getting to the cake underneath. So, when you take a frosted cake out of the fridge, condensation will only accumulate on the outside surface of the frosting, not, beneath it, between it and the cake.
That I *know* of I've only had one severe bubble but it was at an event I attended, so I suppose its possible I have had another few and then customers did not inform me...but I hope not!
The bubble that I had appeared several hours after I set it up, which meant it was as it came to room temp.
When I cut it, I saw that the frosting had separated from the cake...so the air bubble was between the cake and the frosting, NOT between the fondant and the frosting. I think maybe it must somehow come from between the layers.
I also do alot of refrigeration. I think the refrigeration helps keep from getting the middle "bulge" because if everything is firmed up all the way through the cake before adding fondant, then the pressure you are using to smooth the fondant will not cause the cake to settle and bulge the frosting out the sides.
As far as the bubbles...its scary! But I just try to make sure I am not leaving gaps when I spread my buttercream...and also alot of times I use wire/stars and whatever, and I bet on those cakes, or any cake you actually stick something in, helps avoid bubbles. Not sure the answer though...really....
Okay....this is a topic that is of great interest to me on an ongoing basis, and as I read through things, and think about what I do, I am NOT one who refigerates. Ever. Never have. And I stll have bulges....yes, I believe that humidity is huge factor, and my bubbles/ bulges have usually happened during warmer weather. I crumb coat, I let cakes settle and rest overnight, I have a very stiff dam of icing between layers, cakes are iced and decorated in a cool enviornment, and bubbles/bulges still occur, and always on layered cakes, never sheet cakes. Sometimes they occur within hours, sometimes it's happened overnight, and the funny thing is if I take off the icing and re-ice the cake, I don't get a bulge. That's interesting to me. My next thought is that it might be my icing recipe (yes, I use hi-ratio shortening, no butter, meringue powder, corn syrup, water, flavoring, and of course powdered sugar and a little salt). Perhaps this bubble/bulge thing will always be an ongoing dilemma/mystery! I don't always get a bubble or bulge, but when I do, it's certainly frustrating because I always use the same processes. Hmmmm...
Sometimes I think maybe when you take a big chunk of icing and start spreading it over the cake, that there can be a small gap that is air trapped between the cake and icing.
I think maybe if we make sure we are firmly filling the cake and pressing out any air...and then firmly icing the cake with a nice thin crumb coat...and then icing again firmly, making sure no air is being trapped, maybe our chances will be less?
I know that the cake I did that got the air bubble...since it was a freebie I brought to a party, I actually did not let it rest a long time between crumb coating...actually I don't even know if I did crumb coat at all, I think I just iced it...chilled for awhile, and then fondant. So since I combined steps I'm wondering if going faster allowed air to get trapped more easily.
That makes sense...the firmness part....firmly filling, then pressing out air, and firmly icing in smaller amounts. I do sometimes get a large glob, and perhaps I don't press in enough. And, a really light crumb coat. I am guilty of slathering that on sometimes. That all really makes sense to me...thanks Kitagirl! 
Now, for that humidity thing..... 
Has anyone compared the side bulge to the cake flavor/recipe? I am so annoyed with it that I have been driving everyone around me crazy.
The icing dam is always the same, but now I am wondering if the cake density is part of it. I am going to start tracking that with the size of the bulge. My idea is that the weight of the fondant pulls down more on some cake flavors than others which pushes the buttercream out further.
Or....I may have been worrying about this so much that I am confusing myself LOL! I want perfect fondant covered cakes & these bulges are in the way.
So is it the cornstarch? Or is my fondant getting air bubbles because there are air bubbles forming under the buttercream, therefore distorting the fondant?
I always use cornstarch to roll out my fondant and I have read that Sharon (sugarshack) does as well...so I don't think that the cornstarch is your problem......I really, really don't.
Cake flavor doesn't seem to by my problem....it happens on chocolate, white, lemon, whatever. I do however, have a problem with choclate cakes sinking in the middle when I do sheet cakes, or if I do a 1/2 white 1/2 chocolate, the chocolate rising not as high as the white side, even when batter levels are the same. My chocolate also sinks when I do rounds as well. I have figured out to fill chooclate a little bit higher, and bake a little longer, and that seems to help. But the chocolate always sinks, no other flavor.
Last fall I was working on a 4 tier wedding cake on my kitchen counter. It was October so the weather was fine. I have a three light fixture hanging above my counter. All buttercream. Well as I was working on the cake I noticed a huge bubble start to form on one edge of the top tier! Guess what? The cake was so tall it was too close to one of the lights and the heat was causing the bubble to grow! As soon as I moved the cake away from those lights I didn't have anymore problems. It was a crisco/butter BC recipe. So my guess is that the bubbles that grow have nothing to do with fondant and are some kind of reaction with different temperatures between inside and outside of cake? Similar to what Kitagrl experienced. Perhaps the way the cakes are being stored they are in direct line of spotlighting? I can see this happening at a wedding.
Just a thought.
mamawrobin - I sure hope not. cornstarch is the only way I can keep my fondant from sticking.
Mel1965 - mine sink too. I increased the flour by a bit and decreased the liquid by a bit and that seemed to help. And I absolutly cannot touch it to check for doneness or that completely deflates it.
Cake flavor doesn't seem to by my problem....it happens on chocolate, white, lemon, whatever. I do however, have a problem with choclate cakes sinking in the middle when I do sheet cakes, or if I do a 1/2 white 1/2 chocolate, the chocolate rising not as high as the white side, even when batter levels are the same. My chocolate also sinks when I do rounds as well. I have figured out to fill chooclate a little bit higher, and bake a little longer, and that seems to help. But the chocolate always sinks, no other flavor.
I have the exact opposite problem! This is so weird! I use a mix, Pillsbury, and it ALWAYS rises WAY up! Sometimes it will run over the side and drip to the bottom. Do you use a mix or scratch? What brand if it is a mix? I don't fill it very full, and it is always very dense and doesn't sink. I have sinking issues with white and yellow. lol!
sorry what do you mean by flas freezing? do you crumb coat it then ice it the flash freeze before covering with fondant?do you guys fondant it when its nearly forozen is it ?
how long would you call a flash freeze? 1/2 hour?????
non- that's what I was thinking too! I only get the bubbles when my cake goes from a cooler environment to a warmer one!
I usually use Duncan Hines, but I mad a choc cake for my son's birthday this week and used a Betty Crocker super moist, and it did not sink. Didn't seem to have as much batter as DH, but didn't sink, so we were good. Everyone liked it better, too, so I may switch over to BC, at least for chocolate. Adding flour and less liquid is a good idea...I'll remember that!
sorry what do you mean by flas freezing? do you crumb coat it then ice it the flash freeze before covering with fondant?do you guys fondant it when its nearly forozen is it ?
how long would you call a flash freeze? 1/2 hour?????
No..15 minutes tops...you don't want a cold cake just firm. 15 minutes in the freezer won't freeze your cake or change the inside temperature of your cake but it will firm it up good for a nice foundation for fondant. I can get sharper edges when I do it this way.
amysue...I would bet money it isn't the cornstarch...like I said I always use it w/o any problems. So glad that I don't have any either because Michele Foster's works much better when using cornstarch for rolling out. 
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