Melanie - do you mean an air bubble in the icing or has the cake bulged?
Yes Melanie ...... As Katy stated post above? Air bubble or bulge??
I am confused? I have always iced/piped my cakes with cake at room temp... never cold. Room temp icing as well. I may pop in the fridge to firm up crumb coat, but bring it out & let it sit before I apply my icing. Of course, that's how I was taught, by my & 1st Cake teacher. Always done it that way. I am surprised your icing doesn't start to slide off when your cake reaches room temp?? But that doesn't mean your way is the wrong way. Different people, different techniques. I am just wondering if you have created air bubbles in your icing from over beating???
Hard to be completely sure from the photo, but it looks to me like it's one of 2 things
1. Your 'dam' isn't holding up from the weight of the fondant. So your butter cream edging needs to be stiffer
2. Your fondant is sliding down. I'm with June, this could be because you are laying fondant over cold butter icing. As it comes to room temp, you get moisture and your fondant is slipping on it. Or your fondant is too heavy, can you roll it out a bit thinner.
Are you filling/torting your layers? Because as Katy stated above.... if your dam isn't firm enough, it will create a bulge. This happened to me twice. 1st was just as I stated.... dam wasn't firm... icing slid out..... bulge. 2nd time, fondant was too thick & heavy, but that was more like a pucker... but still, not nice. I covered that one with a flower. :o)
Melanie, I'm stumped. I have googled this issue and everyone seems to do something different. Some always chill, some never do! Heck. Ok, in desperation -
Are you letting the cake settle after you have filled it, but before crumb coating?
Try leaving the cake in a cool place, but not the fridge, for the crumb coat to crust and then cover?
I think I might just have an answer - I too suffered the "bulge" and discovered that the main reason is because of a) the cake being too cold (and thus the crumb coat of buttercream or ganache still being too wet); and b) I was rolling my fondant out too thinly. Soo I had the fortune of buying a few tutorials from craftsy, and I think it was the one from Jessica Harris -that pointed me in the right direction. After baking and cooling cake, I trim and fill and cover with crumb coat (I generally use chocolate ganache, it gives a better finish) and then chill cake for at least a day, but certainly overnight. Then I remove from fridge and let it come to complete room temperature! Then I do any corrections to the crumbcoat to make it as smooth as possible and then I stick in the freezer for 10 minutes! This just sets the ganache (or buttercream) as firm as possible and when the cake comes out of freezer, I then lightly smear the outside with some softened crisco (holsum in SA) and then roll out fondant and cover. The fondant must be about 7cm (sorry we use metric in SA) and then I cover and smooth cake - got to work quickly but the beauty is that the holsum allows you to gently pull fondant away from side of cake if you do see an air bubble rather than pricking a hole in side; the other thing is that fondant does not like wet! My first cakes I used to wet sides of cake with sometimes simple syrup or with piping jelly - but almost always got bubbles! Also found that if you knead the fondant you mustn't fold it over itself - rather pust together from sides, push down from top, push together from opposite side, then push down - and so on and so forth! It took plenty trial and error to finally found what worked for me - fortunately many designs allow you to hide the flaws in the fondant, but not so when you are having to produce a cake with smooth background and very little adornment! I do hope that this will be of some assistance :-)
Mandy - that is all very useful information, thanks for posting. Funnily enough I had this problem a little while ago (twice!). Never had it before, when I 'didn't know what I was doing'. But since following tutorials and 'knowing' a bit more, it did happen! Just goes to show that a little knowledge can be a dangerous thing lol!
Oh wow - thanks June, I am going to give your cornstarch idea a try - have a two tier birthday cake for this weekend so a good time to experiment :-)
Interestingly I have tried the book method but didn't have any significant improvement - BUT having said that, that was still in the days when I used to work with "wet" sides and too thin fondant! Honestly no longer have the bulging problem and when I do - its because I roll the fondant too thinly.
Oh the wonderful world of baking - it certainly keeps one on ones toes to constantly strive for perfection :-) Sweet wishes to you all my caking friends xox