So, it was my first time using white chocolate ganache on my cake. It was nice and firm, sharp edges, cooled to room temperature. But once the fondant was placed on the cake, the ganache did not hold up. It became very soft and lumpy and showed through the fondant. With one of my tiers, it actually started coming out of the bottom as I was smoothing out the fondant.

I really dont know what I did wrong, but after this experience I dont think I will be using white chocolate ganache in the future. I used a 4:1 ratio of white chocolate to cream.  

Anyone know what went wrong? 

That's weird, your ratios were fine. Was it hot in the room you were decorating in? It sounds like it melted.

no, it was actually cooler then usual

What sort of chocolate did you use?

Callebaut white chocolate

White chocolate ganache seems to have a higher failure rate than milk chocolate with dark chocolate seeming to be the easiest to achieve success with. Have you tried a 3:1 ratio white chocolate to cream?

No, i thought a 4:1 ratio would probably hold better and be stiffer. I used  33% cream. Could that be the issue?

Sonya73

I just posted a cake., and the  exact same thing happened to me with white ganache.  It's been hot here, and  my hubby shut off the AC when we went out......unbeknownst to me......he turned it on when we got home. So my cake sat in the heat for several hours. Next morning, my cake was oozing. I had to shore it up by piping a small dam of RI around the cake, then added decorative RI piping all around the cake, then into the fridge. What a nightmare. 

I am in Canada. The highest fat content cream that I can buy without going to a specialty store is our whipping cream with a fat content of 35%. I know in the U.S. that there is a heavy cream with 38 - 40% fat. 

I know a lot of people use the 3:1 ratio for white chocolate.

It is strange that it came together well and then broke down afterwards.

Forgot to add that it should be at least 35% cream.

@jchuck Yikes! Thats scary, but nice save! 

@squirrellyCakes Im in Canada aswell and 33% was the highest i could find. Where do you buy your cream? Does 2% more make that much of a difference?

I buy Lactantia which is 35% and actually lately buy it at Giant Tiger but normally at Your Independent Grocer. 

Honestly, I wouldn't think 2% difference should matter much. But then again I know that the difference between our 35% whipping cream and the American 38-40% heavy cream makes quite a difference when used to make whipped cream.

I know that it is always recommended to use 35% cream. I think you may have more luck with the 3 to 1 ratio. Callebaut is excellent quality.

I get my cream at Costco....34% whipping cream.  I think the heat and humidity is what caused my difficulties.. 

2% fat difference shouldn't change the ganache. You said it behaved fine until it was covered with fondant and sitting at room temperature. Sounds like the heat was an issue.

I must say though, I use 4:1 for white choc ganache in the Australian summer (40 deg Celcius plus) with no worries at all inside the house - but I wouldn't leave the cake sitting in the sun.