I don't know if this is considered a "disaster", but it's not good. I have been making buttercream for 3 years using the same Wilton's recipe except I use 1 cup veg shortening instead of half shortening/half butter. I double the recipe so I use 2 cups veg shortening, 2 tsp of vanilla & 1tsp of butter extract, plus milk. Lately my cakes seem to have a lot of "oil" on them... for example when I use ribbon on buttercream cakes the ribbon absorbs the oil & gets greasy looking & I recently did a red BC cake with white scrolls & the next morning the white scrolls on the cake absorbed the red dye & turned kind of a transparent red from the cake (I use air brush dye to make my red BC). The buttercream was a medium to stiff consistancy & wasn't over mixed, it wasn't mushy. What could I be doing wrong? Should I put maybe only 1 tsp of vanilla/1 tsp butter?
Ai would first change from air brush color to gel color -- your flavorings should be fine
It may also be related to the transfats being absent from your veg shortening. They may be "bad" for you, but they make icing darn stable.