I am relatively new at all of this...I have been decorating cakes for less than a year and just recently started doing them for others. I needed to make a wedding shower cake over the weekend. BC with polka dots from a dot impression mat. So I thought, this is no big deal. Shouldn't take too long. Famous last words I guess! I am still using the Wilton BC recipe for now, because I am comfortable with it and I know it works, but this time, I couldn't get it to smooth out to save my life! I waited forever for each layer to crust over and it never really did. I ended up frosting one tier twice! Basically, I ended up with BC that had tiny cracks in it. The cake still looked "okay" and the people were really nice about it, but it drove me crazy to give them anything other than my best.

I know it is more humid here than I am used to (we are new to Austin), but is that what caused it? Or did I make the BC too thin? Any thoughts are appreciated.

My bc was not crusting recently due to the extremely high humidity. It was a different recipe though.

I haven't had to work with high humidity like that but if it is because of the humidity and you will have this same problem in the future, try refrigerating it instead. It works for non-crusting frostings anyway...

Adding a drop or two of white vinegar will usually prevent that from happening.

See this recipe from CakemanOh for info:

http://www.cakecentral.com/cake_recipe-2375-Brite-White-Buttercream-Icing.html

HTH