Hi all - I wanted to practice scroll work, so I covered a cake with fondant and used a basic buttercream recipe with shortening and butter - but as I piped it, I noticed the 'stain' marks happening...and then this morning as the cake sat overnight - it looks like this.  Any idea how to avoid this?

Thank you!

yes--your blue color needs to be kneaded in better--that's all

it's just food color striations

oh, dawny, thank you

hmm--i'm gonna guess--if there is no shortening in your fondant--then the grease in the buttercream is leaching into there?

Yeah maybe the fondant was too dry or had some powdered sugar on the surface which absorbed the oil from the buttercream.

Thank you !

I rubbed Crisco on all the fondant that the scrolls weren't on - and it made it all blend in much better.

I have never used shortening in my fondant...But i'm guessing I need to do that now. I never knew!  Thanks

Hey There - May I ask another question, related? I put round disks of fondant onto my cupcakes that were iced with buttercream last nite.

This morning, they had melted and kind of slumped down over the cupcakes....

1. the fondant discs were made 3 days in advance and had dried out.

2. the decorated cupcakes were placed into closed containers last night.

I just read this in a past forum after searching :I made a cake with gumpaste roses. Straight gumpaste, and the roses had been dried for a good month. I made the mistake of closing the cake up in a cake carrier. In less than three hours the rock hard gumpaste roses and wilted and completely lost their shape. They asorbed moisture even though there was no question about them being completely dried before going in there.

---My question, even though my fondant didn't have Crisco in it, even if it did..This problem would have happened anyways?

How to avoid? Place toppers on at the last moment...But if there is a drive to be made to deliver...Does this always happen?

Thanks!

GP is most often affected by one of two things: humidity, and children. Your problem was humidity -- likely moisture from the cupcakes. If your "closed container" was a plastic box or covered cake pan, that's your problem. This shouldn't happen in a closed cardboard cake box. It also looks like you need a different icing recipe.

AI don't know the science behind it, but sealing fondant or gumpaste decorations in an air tight container cause the fondant/gumpaste to wilt. The same can happen to buttercream. I just leave the containers slightly cracked so that it is not air tight.

The same thing happened to me.   I used those air tight "clam shell" cupcake containers.   GREAT to keep the cupcakes moist....hell on fondant toppers. 

thank you all. glad to know so this doesn't happen again!

So, what I was taught in my cake decorating class (and elsewhere) was basically that you should NEVER pipe buttercream on top of fondant. They simply do not interact well. The fondant absorbs the fat and breaks down, becoming shiny and sticky. The buttercream underneath fondant is fine because that interior surface doesn't have to look good and there is no air in there.

Think about when you're laying your fondant on. Any extra bit that you trim that came in contact with the buttercream is instantly made shiny and sticky. You can't wipe the BC off, the fondant itself is affected.

Whenever you pipe designs on the exterior of a fondant cake you should be using royal icing because it has no fat (just egg whites/meringue powder, water, and sugar). it also works better for gluing fondant pieces onto fondant (unless they're light enough to be stuck on with water).

In my experience, this is all true of both classic Fondant and marshmallow fondant (which I usually use).

I hope this helps!

Not true.  I always and only pipe with butter cream on fondant cakes and NEVER with Royal....to me, royal is for cookies.    Over the years I have used different BC recipes too and never had a problem. 

yayyy thank you for this. I see buddy of Cake Boss also has buttercream in those huge ol' santa bag looking piping bags and he pipes right over his fondant all sorts of swags and flowers. thank you for confirming this.

I might be alone, here - but I think the "leaching" pattern on the OP's picture is kind of cool. I'm thinking of trying to recreate it on purpose!