if I frost cupcakes today for eating tomorrow. do they have to go in the fridge bec. of the milk in the frosting, or can they stay in a container on the table? no room in fridge. TIA.
The safest option is to put them in the fridge. I have left cakes with buttercream frosting on out of the fridge overnight with no ill effects but I can't really endorse it. I figured that since butter can be left out and there is so much sugar in it that it should be fine but the best bet would be to refrigerate the frosting and then frost them tomorrow.
I just did a quick google search and found that most buttercreams are indeed ok to leave out of the fridge - even the ones with a little bit of milk in them. If it has egg yolks in it, then it is advised to refrigerate the frosting.