I'm new to cake decorating and am a little confused about "crusting." I understand you want your frosting to crust to get a smooth finish on your cake, but here's where I'm confused:

For a frosting to crust, must it always have vegetable shortening in it, or can a butter-based frosting crust as well?
Can you turn any frosting into a "crusting" frosting? How?
Is this the same as a stiff frosting? Can adding powdered sugar to stiffen your frosting also make it crust?
When covering a cake in fondant, is it necessary to have a crusting or stiff (or are these the same?) frosting?
Same question as the previous but with modeling chocolate.

Thanks for sharing any tips with the new girl

Hi! I can't answer all of your questions, but one or two I can:

I use an all butter recipe and it crusts very well- you don't HAVE to have shortening to crust.

I dont believe it needs to be a crusting recipe if its going under fondant- I think crusting is more desireable if you want to keep the shape you pipe e.g. roses etc. Non crusting should be fine to cover up as its only really there for taste and to hold the fondant onto the cake.

What makes a buttercream crust- unfortunately I don't know this myself! Its more scientific than my knowledge covers, but I'm sure someone else will know the answer to this

HTH!

I too use an all butter recipe and it crusts fine.

What makes a buttercream crust is the sugar to fat ratio...the higher the amount of sugar:fat, the more "crust" you'll achieve.

Some people believe that adding meringue powder to their buttercream will make it "crust", but it's purely the sugar to fat ratio that determines how much or how little it will crust.

At least that's what I learned in culinary school.

Cakestyles is right.

To answer your other question, not every recipe can be turned into a crusting one. The meringue buttercreams, like Swiss and Italian meringue buttercreams, are not meant to crust and they don't use powdered sugar. I mean, I guess if you wanted to dump a few bags of PS into the recipe after the fact it would probably crust, but it would be gross LOL.