I have a cake due tomorrow and I went to put my buttercream on today and it would not crust. I was using a crusting buttercream so I am not sure what happened.

I used my buttercream that I had in the fridge for about a week now and I had to dye it blue. I usually add the color and mix it in by hand but I was lazy today and did not feel well so I mixed the dye in using my kitchen aid. Could that have made it not crust? Did I mix it too much?

Any thoughts would be appreciated!!!

Is it hot and humid where you live? Your home unusually hot or humid? Raining?
When and how you add color makes NO differrence what so ever. Neither should the fact it has been in the frig.
Are you sure yuou made the recipe *exactly* right.
Usually when a b'cdream does not crust there is more fat than sugar. Maybe you added extra butter or shortening w/o realizing it.

Did you use the buttercream while it was still cold?
Was your cake cold at all?
What is the weather like right now where you are at? is it humid?

I dyed it right out of the fridge. I am sure I did the recipe right because I used it last week and it crusted just fine. Maybe it was the weather.....ughhh I hate when this stuff happens and it is a trial and error to figure out what went wrong! Thanks for all the thoughts.

I refrigerated a buttercream crumbcoated cake once and it never did crust after I removed it from the fridge. I don't know why but I haven't refrigerated buttercream since.

Crusting/non-crusting is a function of the fat to sugar ratio. Period.

Has nothing to do with refrigeration, color, mixing or meringue powder.

The moisture in the change of temperature + adding the color to it might have thin the icing a bit causing it not to crust.
Edna