I have always used the Wilton buttercream recipe (crisco, water etc) But tonight I tried a recipe that uses 1/2 cup crisco, 1/2 cup butter, ps, flavorings and whole milk--(I used half and half). Now, do I have to refrigerate the cake if I'm icing it tonight and eating it tomorrow?
If not how come?
Depends how hot it is where you are. The butter & half & half are not going to make anyone sick but it might get really soft & slide off your cake!!
That's how I make my BC and it's fine without being refridgerated. Not sure the science behind it all though.
I do not use milk in my butter cream, I always use water. I always refrigerate my cakes though. I find the icing holds up better and I also think a chilled cake tastes better....