here is a mini wedding cake i was working on this weekend... Colorado is a very dry state and i 've never had this problem before... this week it rained for 5 days straight and it was very clamy and humid out... i covered this cake with bc and it just wouldnt dry or crust.. it just kept slidding down the cake.. so i scrapped the icing off and made a new batch of very thick very sweet bc.. it looked wonderful but within minutes it turned into a watery glaze.. i used very little water when smoothing it out.. i tried freezing it, not freezing it.. nothing worked.. does anyone have any suggestions with bc and humidity.. i have 2 big wedding cakes coming up and like i said i have NEVER had this problem before... i dont know what the weather will be like and dont want to run into this.. needless to say i didnt charge my customer.. i had to run to the store and buy a sponge cake and throw some borders and the chocolate decorations on it that i had... 
are you using crisco or all butter. Shouldn't happen if you use hi ratio shortening stands up better in humidity.
I use meringue powder. I have found that it helps my frosting to set better. Good luck!!! Awww, so sorry you had this problem! I have been having issues with humidity too...I live in Maryland...and man, does it ever get humid here! I had issues with fondant last weekend from the high humidity. I used LOTS of decorations to cover up those problem areas. Better luck next time!
I am also finding that I will have to use meringue powder. I live in Florida, where it is always humid, more so in the summer. I have to turn my air conditioner waaaayyyy down to about 74, and make sure it's very cool in the house before starting the cake. also, i have been noticing that my cakes come out better if i frost and decorate them at night when the sun isn't beating thru the windows. I always use all crisco, but this is my first summer "officially" doing cakes, and I am finding out all kinds of differences in how the seasons affect the texture. mine has been real tacky, and also doesn't crust as firmly as it did in, say, march.
good luck, let us know if you find any tricks or solutions!
I use 4 cups of icing sugar and 1 1/2 tablespoons merangue powder and 1/2 cup butter & 1/2 cup crisco, 1 tsp of vanilla and about 3 tblsp of water. This always crusts for me and then I put it in the fridge. If transporting be sure to cool the car down first.
Hope this helps
Kathy
The meringue powder is an interesting issue. I have made buttercream icing on a number of occasions without the use of meringue powder and it always crust over and I never have an issue. In one of the Wilton courses I took I did not use meringue powder for my final cake and my instructor was pointing out to the class how I ended up with a perfect finish because of The meringue powder I used. She almost died when I told her I did not use any. So here is the new question, does meringue powder really stabilize buttercream icing or is it another factor?
I have never used meringue in my frosting before. It normally comes out great without it. I also noticed that when I tried to make a small amount of red (without the meringue), the color didn't blend smoothly with the frosting. It looked like it was separating, or just kind of beading up. It was really strange. I can only attest all these things to the humidity, don't know what else it could be.
This is the recipe I use and I live in Houston, Texas!
1 c butter
2 c crisco
1 tsp each of vanilla and butter extract
8 c sifted powdered sugar
2 tbl water ( I use way more water, only because i like mine to be really creamy so i can frost my cake, but this depends on how much you want to use & only add a little at a time)
I used this recipe about 2 weeks ago on a mickey mouse cake i made for a family member who doesnt know what a/c is?!! and it didnt melt!
Here is a simple cure I use all the time. I live in NJ and the weather can get quite soupy in the summer. When I take a fondant cake out of the frig and get condensation, I take out a table fan and set it near the cake. The stream of air drys the cake and no more weepy fondant.
Good Luck and Drier Cakes!
Junebuggey
Here in the UK it's humid most of the time and the bigger cake decorating people have to invest in de-humidifiers for their kitchens. You can also get de-humidifying containers for placing decorations in to allow them to dry.
Thanks everyone.. like i said it was a very weird weather pattern... i've never added the meringue but i certainly will start to consider it.. i have a huge wedding coming up in August and i'm scared to death now.. i've done hundreds of wedding cakes and now i'm worried..
Quote by @%username% on %date%
%body%