I'm making a cake and dropping it off at the venue about 7 hours before it starts (they want to get everything set up early). The cake has a rapsberry preserve filling as well as coconut buttercream (containing coconut milk). I'm advising them to refrigerate it but I'm worried that there is no commercial refrigerator at the venue to store the cake until the reception. Anyone know if it's safe to leave it out at room temp for 7 hours with preserves and coconut buttercream?
The preserves will be fine. The buttercream would be hard to say unless we knew just how much coconut milk was in it. Do you know the general shelf life of coconut milk? I mean, I know it's called "milk" but it's a vegetable product, I can't imagine that it would spoil quickly the way dairy would. While you're awaiting an answer, try to see if you can check that out online somewhere! Keep in mind too, that the nominal amount you use, when paired with all of that butter/shortening and powdered sugar, will probably not be enough to spoil anyway.
Sorry that's not a definitive answer, but hope it helps point you towards getting some more good info.
I use preserves in nearly all my cakes. I don't put any cakes in the fridge, so it can sit at room temp for days with no problems. I doubt the coconut milk would be a problem either - it isn't dairy.
The point of using preserves over home made fillings is that they can sit out for long periods of times with out any issues. I use preserves all the time and never put those cakes in the fridge.
Fat goes rancid. There is not fat in raspberry preserves. The high amount of sugar in them will help prevent them from spoiling for a very long time. Eventually, they would mold, but it would take a while.
The coconut milk and buttercream does have fat in it, but it does that a lot longer than 7 hours at room temp for something to go rancid.
I make coconut cake & coconut buttercream with real coconut milk and it sits on my counter for 3 days & is fine. It may even last longer, but I have a 3-day rule where I toss all food after 3 days, not just cakes.