Sorry if this has already been asked, but I couldn't find an answer.

I'm going to try it for the first time in a few weeks for a 5-year-old's birthday cake. It's an outdoor party, so I'm worried about if it will be "good" if it's not refrigerated since it does have milk in it.

Or can I substitute water for the milk?

TIA from a newbie!

Nope. I've never refrigerated it.

Milk and sugar stablize each other.