I made a two tier cake with chocolate mouses filling. Because of a time constraint I had to fill the cake and frost it on Wed. I completed the fondant decorations on Friday and the party was Saturday morning.

On the drive to the party, I could see the cake starting to slide on its layers, I tried to hold it as still as possible but I could see the tiers just wobbling like mad. My 2nd tier was sitting on the straw supports but I could see space in between the cakes, so the bottom tier had settled and the frosting was getting all built up as the inside layers shrunk. It was weird. The top tier started to do the same, I could see the frosting start to slide off the back.

When we arrived at the party, I removed the top tier and it was a soft mess. I was able to use the bottom tier as the centerpiece and re-attach the fondant pieces and nobody said it looked weird, but I knew it was not nice and straight as when i left the house.

When we cut the cake, it seemed like the mousse had almost all been absorbed by the cake. And the very center of the cake was so mushy that I didn't serve it at all. Everyone seemed to think the cake was good, I thought it was super moist, I guess b/c of the absorb mousse.

I did let the cake sit out for a couple hours before we left, but I'm not sure if it would have made a difference, I htink the ckae had already absorbed the mousse by then and it just was supportive enough anymore.

Does anybody have advice on how to handle a mousse filled cake, or any mousse recipes that might be more stable?

Thanks!

AWhat kind of mousse did you use?

AEithe use ganache or butter cream as a barrier between layers. Put down your first cake layer, ice very thinly with bc or ganache. Make your dam and then fill with mousse. Before you add your next layer maybe you want to put s thin layer of ganache or bc on the bottom of that layer ( the side that will be touching the mousse ).

Was this REAL, meringue based chocolate mousse made with eggs & cream????  How long was it at room temp [combining decorating time, travel time, display time, & after cutting time]?  All of that added together should be no more than 3-4 hours.

It sounds like the mousse wasn't stabilized, broke down, and soaked into the cakes--as a result of destabilization and possibly being at room temp too long.

I have had similar issues with mousse (not real mousse, just whipped chocolate cream). I love Kay's idea to put down a very thin layer of ganache to keep the mousse from soaking in if it seperates! I am totally going to use that!!!
 

Soaking in can be an issue, but if the mousse isn't stabilized [generally with gelatin], it will deflate when weight [the upper cake layers, icing, etc.] is put on it, too.  This causes shifting, bulging, and shrinking.

Yes, I think the mousse just broke down and absorbed into thecake . I used a mix from the store for the mousse, it was similiar to a pudding mix and was made using milk. I didn't want to use an egg-based mousse because it was for a kids party.

I did have a thin layer of buttercream on the base of each mousse layer, but I guess it didn't help.

Guess I have some experimenting to do!

Thanks for your responses.