hello, help with this confusing matter.

Should smbc be treated like Chantilly? I mean, should I keep it cold in order to decorate my cake with it and not lose constancy ?

Whenever I use Swiss Meringue Buttercream to ice a cake, I always use it at room temperature. If you put swiss meringue buttercream into the fridge, it will harden due to the large amount of butter in the recipe. Then you would have to wait for it to get back to room temp. So once my batch is mixed up and ready to go, I use it right then and there to ice my cake.  Hope I helped. 

Rebeca 

ASwiss meringue buttercream should stay at room temperature. It will harden into a solid shell, like a stick of cold butter if you chill it. This makes it great for using under fondant, as you can easily cover it when hardened and get a beautiful smooth surface with crisp edges. It must come back to room temlerature before being eaten, though.

AThank you. I was terrible wrong. I saw a video where the person used smbc to cover a cake and the put it in the fridge, she said so it didn't melt down.

I appreciate it ;)

One of the beauties of SMBC is that you work with it at room temp, then chill it up hard to smooth and get very sharp corners--with or without covering with fondant.  I keep my SMBC cakes chilled hard after finishing and they are very stable for transportation to the venue then thaw out by time it is to serve.  when working with SMBC the temperature are used as a tool.