Hello everyone :)

I know there are already a bazillion ganache questions on this forum (and I'm pretty sure I've read almost all of them over the past couple of weeks!) but I'm hoping someone can still help.

So I'm planning to use ganache instead of buttercream under my fondant for the first time. I'm using white chocolate (Sephra couverture callets) & milk chocolate (Callebaut 33.6% callets). 

With the white chocolate, I initially used a 3:1 ratio (using whipping cream with a 38.9% fat content) and it set SO solid. Obviously it has to be thick enough to hold a good shape under fondant, but this was rock hard. I had to microwave it every two minutes or so to continue to be able to spread it, and when it had set on the cake it was almost impossible to cut through and broke off the cake in slabs when I tried to.

I'm so confused because I regularly read of people using a 4:1 ratio!? 

I've tried a few other batches at varying ratios, and I currenltly have a 2.14:1 ratio (oddly specific, I know) which is peanut butter consistency when warm,  firm but spreadable at room temperature and firm when chilled. 

But I just can't understand why it's taken a ration of close to 2:1 to achieve this with white chocolate?!

My second issue....

With the milk chocolate, a 2.5:1 ratio seems to be okay, if a little difficult to spead. I may experiment with the ratio, but for now my issue is with the melting of the chocolate. 

I've been making the ganache by placing the callets in a ceramic or plastic bowl. I then bring the cream to just boiling and pour it over the chips. I leave it a few minutes then stir with a silicone spatula. 

However, this never even nearly melts the callets, so I will put the mixture in the microwave in four or five second bursts (I'm very cautious), stirring between each. Not only is this ridiculously tedious, but it has split my ganache EVERY. SINGLE. TIME. Aarghhhh. 

So so I will have a curdled mixture full of unmelted chocolate. I let the ganache chill, beat it back together, then put in the microwave for another five-seconds-ish. Boom - curdled ganache, chocolate still not melted. 

So my two questions are:

1. Why do I need such a low ratio of white chocolate to cream to get the proper consistency, compared to others?

2. How can I ensure my chocolate is fully melted but avoid encouraging the ganache to separate?

What am I doing wrong? I'm in the UK, so it's fairly chilly but not freezing weather-wise right now. Please help...I'm pulling my hair out!

And thank you so much to anyone who takes the time to read such a long and dull post :)

Hi, I'm not sure about the white chocolate ganache as I have only done chocolate but I would try heating the cream and chocolate together over the stove stirring constantly. it usually helps me to look at different recipes and techniques when having these types of problems. I hope that helps!

look at Rose Warnick's youtube about white chocolate ganache-very helpful!

Thanks so much to you both! I wanted to avoid heating both the chocolate and cream together as that makes it so easy to overheat the cocoa butter and encourage separation, but after seeing the Rose Warnick video, I might have a try at adding the chocolate to the pan of boiling cream rather than the other way around, if that sound like a good idea?

I wouldn't worry about having such a different ratio with your white chocolate, your particular climate can make all the difference.   As long as you have found what works for you, that is what is important.

With regards to fully melting your chocolate, the finer you are able to chop your chocolate, the easier it will melt.  If you have a large amount, you could put it into a food processor and pulse it.

When your ganache splits, add a splash of cold whipping cream and mix it again.  I don't remember why this works, but when I was in a bind myself (also pulling my hair out), I remember reading this - and it worked! 

typically you need more white chocolate. i'm wondering if you were actually using white chocolate? couverture usually indicates a compound chocolate or coating chocolate, which doesn't have cocoa butter in it. Check the ingredients on your sephra and see, this could be the issue.