I did that wrong. The question is , my buttercream does not crust. Will it be ok to use if I then cover with fondant. Not much experience with fondant, will it slip too much?

As far as I know. (I am just starting to learn cake decorating) you can use non crusting butter cream and cover it with fondant. The only problem is when you lay the fondant on the cake, if you need to move it, you will have to make sure that the part that you cut off has not touched butter cream, else you will have to finish up that fondant. Apart from that, I don't see any problem with this. In fact, non crusting butter cream helps fondant adhere to the cake very easily.

I always used the kind that doesn't crust and my fondant was fine. I just didn't put it on quite as thick as I normally would, but I didn't skimp either.

I use SMBC (swiss meringue buttercream) on all of my cakes.. it doesn't crust at all. I have no problems with it at all. Infact.. if your BC has a good crust on it.. the fondant won't stick to it so I personally think that non-crusting BC's are better for fondant. I pop my cake in the fridge to allow the BC to get firm and then lay on the fondant. This way you can have a nice thick BC layer under your fondant and it won't all squish out the bottom when you are smoothing it.

Ditto Jkalman.

Whew! Thanks you guys. Love this site! Gonna give it a shot. Wish me luck.

It can stay out for a couple days.. there's enough sugar in it to preserve it. And you can put fondant (not MMF but real fondant) in the fridge.. you just have to get it to room temp before you touch it. Sometimes you will get some condensation but it will dry and be fine. When I have a fondant cake that needs to be in the fridge I will wait to do the detail work until the day of and it's at room temp so that colors won't run (think royal icing).

Thanks Jeanne! My cakes are about to get a lot yummier!