I made a 3:1 white chocolate ganache yesterday, and allowed it to sit overnight. Today, the ganache was peanut butter consistency, and perfectly thickened. Well, I whipped it for a few moments, and now it seems to be way to soft! It is now more of a whipped cream consistency. I firmed it up for a few minutes in the fridge before I filled and frosted my cake, but as I have had past problems with buttercream bulges in my cakes, I pressed down on the cake when filled, and a ton of ganache squeezed out. This cake is due on Saturday, but this is my first time working with ganache, so I thought it best to work way ahead...

I plan to wait until tomorrow morning, and cover my cake with fondant and monitor for several hours. If there are bulges. I will definitely scrape off and use buttercream instead. But in the meantime. what could have gone wrong? Was it the whipping?

over whipping usually turns the ganache into butter. 

did you use real white chocolate, with cocoa butter, or did you use white chips?

my ratio is 50-50. Perhaps this difference, made the difference. 

jen

I followed a recipe that I found here, I forget who by. I used a mix of Nestle white chips, bakers white, and true white chocolate. I guess I asked for trouble by not searching out enough of the real stuff to work.

It seems to be firming up on the cake, as it sits room temp on my counter...

So I will assess in the morning if it is salvageable, by covering in fondant. If issues arise, I'm scraping off and spackling! I already have spackle mixed up. I'm praying and crossing my fingers. sigh.
 

Is this the recipe you followed??? http://cakecentral.com/a/white-chocolate-buttercream-2 It says buttercream, but it is indeed a white chocolate ganache....and it's a fantastic recipe and crusts beautifully!