I was wondering how long buttercream will keep on the counter. The recipe I use is 1/2 butter 1/2 hi-ratio with milk.
If its actually on the cake, I have decorated using the same kind of icing on Thurs for a Sat cake and it is fine. Although I now have started using water instead of milk and I have noticed no difference in the icing. If its in the bowl, the bowl I had that I forgot about has been out for a week and I noticed melted butter in the bottom of the bowl. I usually stick it in the fridge and bring it to room temp and beat it a few times prior to using.