So I'm doing a small section of black ganache on a cake later in the week. I'm using the Wilton black chocolate melts (essentially white chocolate) and heavy cream. I did a trial run about an hour-ish ago. (I added a little of the gel coloring to it also because the cream lightened it to a purple rather than the black.)

Anyway, I poured it over the frosting, and it's chilling in the refrigerator right now. Great color, great appearance. HOWEVER, I think I used way to much heavy cream, and it's still rather liquid-y after an hour. (Who am I kidding, its a more liquid consistency than pudding.)

What ratio of the white chocolate to the cream should I have used to get a stiffer ganache? Kinda fudge-like in consistency so it stiffens up enough that I could pipe on top of it? (I wanted to pipe "Happy Birthday" in frosting, with some piped stars (like you would do on a character cake.)

Help? Please? I only have enough ingredients to test it out once more, then I have to spend money to buy more that I just don't have right now. lol

Dark chocolate is a 2:1 ratio but white or milk is a 3:1. I've melted more chocolate and added it in to my ganache when I needed it stiffer.

A

Ok great, I'll give it a shot! Thank you :-)

You may be running into trouble because of the candy melts not being actual chocolate.  I'd use pure chocolate and color it black.  If you want to make white chocolate ganache, use pure white chocolate - candy melts aren't chocolate.